UNITED STATES – FINAL ANTI-DUMPING MEASURES ON STAINLESS STEEL FROM MEXICO
Document: Report of the Appellate Body
Date: 30 April 2008
Document codes: WT/DS344/AB/R
Complainant: Mexico
Respondent: U.S.
Third parties: Brazil, Chile, China, EU, Japan, South Korea, Thailand
Dispute stage: Mutually Agreed Solution
Agreements cited: Art. 1, 2.1, 2.4, 2.4.2, 9, 18.4  Anti-dumpingArt. VI:1, VI:2  GATT 1994Art. XVI:4  Agreement Establishing the World Trade Organization

UNITED STATES – FINAL ANTI-DUMPING MEASURES
ON STAINLESS STEEL FROM MEXICO

AB-2008-1

Report of the Appellate Body

APPELLATE BODY

Mexico, Appellant
United States, Appellee

Chile, Third Participant
China, Third Participant
European Communities, Third Participant
Japan, Third Participant
Thailand, Third Participant

 AB-2008-1

 Present:

Ganesan, Presiding Member
Bautista, Member
Sacerdoti, Member

I. Introduction
1. Mexico appeals certain issues of law and legal interpretations developed in the Panel Report,
United States – Final Anti-Dumping Me asures on Stainless Steel from Mexico (the "Panel Report").
1
The Panel was established to consider a complaint by Mexico concerning the calculation of margins
of dumping by the United States Department of Commerce (the "USDOC") based on a methodology
that does not fully reflect export prices that are above normal value.2
2. Before the Panel, Mexico claimed that:
 (a) "model zeroing in investigations" 3 is, as such, inconsistent with Articles VI:1
and VI:2 of the General Agreement on Tariffs and Trade 1994 (the "GATT 1994"),
Articles 2.1, 2.4, 2.4.2, and 18.4 of the Agreement on Implementation of Article VI of
the General Agreement on Tariffs and Trade 1994 (the "Anti-Dumping Agreement"),
and Article XVI:4 of the Marrakesh Agreement Establishing the (the "WTO Agreement")4;

1, 20 December 2007.
2Panel Report, para. 2.1.
3According to Mexico's description, "model zeroing in investigations" occurs when the investigating
authorities compare the weighted average normal value and the weighted average export price for each model of
the product under consideration and treat as zero the resu lts of model-specific comparisons where the weighted
average export price exceeds the weighted average normal value, when aggregating co mparison results in order
to calculate a margin of dumping for the product as a whole. (See ibid., paras. 2.1 and 7.7)
4Ibid., para. 3.1(2).

 (b) model zeroing, as applied in the original investigation at issue in this dispute
5, is
inconsistent with Articles VI:1 and VI:2 of the GATT 1994, Articles 2.1, 2.4, 2.4.2,
and 18.4 of the Anti-Dumping Agreement , and Article XVI:4 of the WTO
Agreement 6;
 (c) "simple zeroing in periodic reviews" 7 is, as such, inconsistent with Articles VI:1
and VI:2 of the GATT 1994, Articles 2.1, 2.4, 9.3, and 18.4 of the Anti-Dumping
Agreement, and Article XVI:4 of the WTO Agreement 8; and
(d) simple zeroing, as applied in the five periodic reviews at issue in this dispute 9, is
inconsistent with Articles VI:1 and VI:2 of the GATT 1994, Articles 2.1, 2.4, 9.3,
and 18.4 of the Anti-Dumping Agreement , and Article XVI:4 of the WTO
Agreement.10
3. In the Panel Report, circulated to Members of the World Trade Organization (the "WTO") on
20 December 2007, the Panel found that "model zeroi ng in investigations" is, as such, inconsistent

5USDOC, Notice of Final Determination of Sales at Le ss Than Fair Value: Stainless Steel Sheet and
Strip in Coils from Mexico, United States Federal Register , Vol. 64, No. 109 (8 June 1999) 30790,
subsequently amended as Notice of Amended Final Dete rmination of Sales at Less Than Fair Value and
Antidumping Duty Order: Stainless Steel Sheet and Strip in Coils From Mexico, United States Federal
Register, Vol. 64, No. 143 (27 July 1999) 40560 (Exhibit MEX-5.A submitted by Mexico to the Panel).
6Panel Report, para. 3.1(1).
7According to Mexico's description, "simple zeroing in periodic reviews" occurs when the authorities
compare the prices of individual expor t transactions against monthly weight ed average normal values and treat
as zero the results of comparisons where the export pri ce exceeds the monthly weighted average normal value,
when aggregating comparison results in order to calculate a margin of dumping for the product as a whole.
(See ibid., paras. 2.1 and 7.7)
In our discussion, we use the term "periodic review" to describe the "periodic review of the amount of
[anti-dumping] duty" as required by Section 751(a) of the United States Tariff Act of 1930 (the "Tariff Act").
That provision requires the USDOC to review and determine the amount of any anti-dumping duty at least once
during each 12-month period beginning on the anniversary of the date of publication of an anti-dumping duty
order if a request for such a review has been received. However, in the case of the first assessment proceeding
following the issuance of the Notice of Antidumping Duty Order, the period of time may extend to a period of
up to 18 months in order to cover all entries that may have been subject to provisional measures.
8Panel Report, para. 3.1(3).
9The five periodic reviews challenged by Mexico are listed in Exhibits MEX-5.B through MEX-5.F
submitted by Mexico to the Panel; further details may be found in Panel Report, para. 2.2.
10Panel Report, para. 3.1(4).

with Article 2.4.2 of the Anti-Dumping Agreement 11, and that the USDOC acted inconsistently with
this provision by using model zeroing in the original investigation at issue. 12 However, the Panel
found that "simple zeroing in periodic reviews" is not, as such, inconsistent with Articles VI:1
and VI:2 of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping Agreement, and that,
accordingly, the USDOC did not act inconsistently w ith these provisions by using simple zeroing in
the five periodic reviews at issue.13
4. On 31 January 2008, Mexico notified the Dispute Settlement Body (the "DSB") of its
intention to appeal certain issues of law covered in the Panel Report and certain legal interpretations
developed by the Panel, pursuant to Article 16.4 of the Understanding on Rules and Procedures
Governing the Settlement of Disputes (the "DSU"), and filed a Notice of Appeal 14 pursuant to Rule 20
of the Working Procedures for Appellate Review15 (the "Working Procedures"). On 7 February 2008,
Mexico filed an appellant's submission. 16 On 25 February 2008, the United States filed an appellee's
submission17, and Chile, the European Communities, Japan, and Thailand each filed a third
participant's submission.18 On the same day, China notified its intention to attend the oral hearing as a
third participant.19

11Panel Report, para. 8.1(a). However, the Panel did not recommend to the Dispute Settlement Body
that it request the United States to bring its model zeroing procedures into conformity with its WTO obligations
under the covered agreements because of its earlier finding that the United States had abandoned that practice as
from 22 February 2007. ( Ibid., para. 7.45) The Panel explained that it "fail[ed] to see what purpose would be
served by a recommendation relating to a measure that no longer exists." (Ibid., para. 7.50) The Panel exercised
judicial economy in relation to Mexico's claims under Articles VI:1 and VI:2 of the GATT 1994, Articles 2.1,
2.4, and 18.4 of the Anti-Dumping Agreement , and Article XVI:4 of the WTO Agreement regarding "model
zeroing in investigations". (Ibid., para. 8.2(a))
12Ibid., para. 8.1(b).
13Ibid., para. 8.1(c) and (d). The Panel exercised judicial economy in relation to Mexico's claims under
Article 18.4 of the Anti-Dumping Agreement and Article XVI:4 of the WTO Agreement regarding "simple
zeroing in periodic reviews". (Ibid., para. 8.2(b))
14WT/DS344/7 (attached as Annex I to this Report).
15WT/AB/WP/5, 4 January 2005.
16Pursuant to Rule 21 of the Working Procedures. Along with its appellant's submission, which it filed
in Spanish, Mexico provided a courtesy English translation and an English executive summary of its appellant's
submission. On 8 February 2008, Mexico provided an executive summary of its appellant's submission in
Spanish to the Appellate Body and to the United States a nd the third participants. In view of the fact that
Mexico filed the appellant's submission in Spanish and the executive summary in English on the due date, and
that the Spanish executive summary wa s filed after the deadline for filing an appellant's submission, the
Appellate Body Division hearing the appeal informed the participants and the third participants that it
considered the Spanish version of the executive summary to be a courtesy translation.
17Pursuant to Rule 22 of the Working Procedures.
18Pursuant to Rule 24(1) and (3) of the Working Procedures. On 29 February 2008, the participants
and the third participants were provided a courtesy English translation, prepared by the WTO Language
Services and Documentation Division, of Chile's third pa rticipant's submission originally filed in Spanish on
25 February 2008.
19Pursuant to Rule 24(2) of the Working Procedures.

5. By letter dated 8 February 2008, Mexico requested authorization from the Appellate Body to
correct a clerical error in its appellant's submissi on, and two clerical errors in the executive summary
of that submission, pursuant to Rule 18(5) of the Working Procedures . On 12 February 2008, the
Appellate Body Division hearing the appeal invite d the United States and the third participants to
comment on Mexico's request. No objections to Mexi co's request were received and, on 14 February
2008, the Division authorized Mexico to correct the identified clerical errors.
6. The oral hearing in this appeal was held on 6 March 2008. The participants and the third
participants, with the exception of China, made or al statements and responded to questions posed by
the Members of the Division hearing the appeal.
7. During the course of the appeal, the Division r eceived a request pertaining to a procedural
matter. By letter dated 3 March 2008, the Europ ean Communities requested the Appellate Body to
clarify whether the United States' appellee's submissi on was considered to be filed with the Appellate
Body within the meaning of Rule 18(1) of the Working Procedures . The European Communities
pointed out that the Working Schedule for this a ppeal, communicated to the parties on 1 February
2008, provided for the United States' appellee's submission to be filed by Monday, 25 February 2008,
at 5:00 p.m. However, the electronic version of the United States' appellee's submission was sent to
the Appellate Body by e-mail only at 7:56 p.m., and the European Communities presumes that printed
copies were delivered to the Appellate Body after that time. As a result, the United States "had
significant time to examine the filings of the Thir d Participants and eventually adjust its own
submission prior to filing."
20 At the oral hearing, the European Communities reiterated its request that
the Appellate Body clarify whether it considers th e United States' appellee's submission to be filed
within the meaning of Rule 18(1) of the Working Procedures, and what the consequences are, if any,
of a late filing.21

20Letter from the European Communities to the Appellate Body Secretariat, dated 3 March 2008, p. 2.
(emphasis omitted)
21This issue is addressed at, infra, paras. 163 and 164.

II. Arguments of the Participants and the Third Participants
A. Claims of Error by Mexico – Appellant
1. Simple Zeroing, As Such, in Periodic Reviews
(a) Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of
the Anti-Dumping Agreement
8. Mexico submits that the Panel erred in finding that simple zeroing in periodic reviews is not,
as such, inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the
Anti-Dumping Agreement. Mexico requests the Appellate Body to reverse this finding and to find,
instead, that simple zeroing in periodic reviews is, as such, inconsistent with these provisions.
Mexico's appeal is based on several arguments.
9. First, Mexico argues that, in any anti-dumping proceeding—including periodic reviews under
Article 9.3 of the Anti-Dumping Agreement—"the margin of dumping must be calculated in respect of
individual exporters or foreign producers subject to such proceeding and for the product under
consideration taken as a whole." 22 Once the authorities define the product under consideration, the
scope of that definition also determines the sc ope of the authorities' dumping determination.
Therefore, dumping as defined in the GATT 1994 and the Anti-Dumping Agreement cannot exist in
relation to a specific type, model, or category of the product under consideration or in relation to
individual export transactions. It follows that, when the calculation of dumping involves multiple
comparisons between normal value and export price, the results of the intermediate comparisons are
not "margins of dumping" but, rather, "inputs to be taken into account in the determination of the
margin of dumping for the product under considera tion as a whole for each known exporter or foreign
producer."23 This is also borne out by the context pr ovided by Articles 6.10, 9.4, and 9.5 of the
Anti-Dumping Agreement. On this basis, Mexico argues th at Article 9.3 requires investigating
authorities to aggregate the results of all the co mparisons when calculating the overall margin of
dumping, and that the results of intermediate comparisons cannot be selectively ignored or
disregarded. By contrast, the Panel's "reasoning" 24 inappropriately permits margins of dumping to be

exportadores individuales y productores extranjeros sujetos a dicho procedimiento y para el producto objeto a
consideración tomado en su conjunto").
identificado").
24Ibid., para. 8 ("el razonamiento").

defined differently under different contexts or syst ems of administration, which is contrary to the
uniform definition of "dumping" provided for in Article 2.1 of the Anti-Dumping Agreement.
10. Secondly, Mexico contends that the Panel erred by concluding that anti-dumping measures
are concerned with the pricing beha viour of importers in relation to individual import transactions.
For Mexico, there is no support for such a conclusion in the text or context of the relevant agreements.
As the Appellate Body has confirmed, margins of dumping do not exist for individual importers or
transactions but, rather, they are related to the pr icing behaviour of exporte rs and foreign producers
with respect to their exports of the product under consideration.
25 Mexico rejects the Panel's reliance
on Article VII of the GATT 1994 in support of th e proposition that the word "product" may be
interpreted on a transaction-specifi c basis. That Article is concerned with the amount of customs
duties to be applied on each import transaction, a nd therefore it provides an "entirely different" 26
context to the term "product" than the one provided for in Article VI, which is concerned with the
pricing behaviour of exporters and foreign producer s. Mexico also emphasizes that the Panel's
interpretation of the term "produc t" cannot be reconciled with the investigating authority's duty to
make an injury determination on the basis of all th e sales made by an exporter or foreign producer of
that product.
11. In addition, Mexico suggests that, by referring to an importer's margin of dumping, a concept
for which there is no textual support in the Anti-Dumping Agreement, the Panel mistakenly equated
the system for collection of anti-dumping duties from i ndividual importers with the rules that must be
followed for calculating margins of dumping for indi vidual exporters. According to Mexico, liability
to pay anti-dumping duties may be based on a specifi c transaction. However, the rate and amount of
that payment is subject to the ceiling provided in Article 9.3, which is the margin of dumping
calculated for the exporter or foreign producer under Article 2 of the Anti-Dumping Agreement .
Mexico characterizes as "factually incorrect" 27 the Panel's assertion that the obligation to pay anti-
dumping duties is not incurred on the basis of a comp arison of an exporter's total sales but, rather, on
the basis of an individual sale between the exporter and its importer.
12. Thirdly, Mexico argues that the Panel erred in concluding that the existence of a "prospective
normal value" system under Article 9.4(ii) of the Anti-Dumping Agreement lends contextual support
to the view that "'anti-dumping duties can be determined on a transaction-specific basis' under

25See Mexico's appellant's submission, para. 47 (referring to Appellate Body Report, US – Zeroing
(Japan), para. 111).
26Ibid., para. 44 ("totalmente distintos").
27Ibid., para. 50 ("factualmente incorrecta").

retrospective systems such as that employed by the United States." 28 The Panel's contextual
arguments erroneously conflate the amount of duty that is permitted to be collected from the importer
under a prospective normal value system and the exporter's "margin of dumping". The Appellate
Body has consistently distinguished between these two distinct concepts. 29 According to Mexico,
"it is precisely because the amount of duties coll ected from importers under a prospective normal
value system may differ from the actual 'margin of dumping' of the exporter or producer, that
Article 9.3.2 requires an opportunity for a review." 30 While the Anti-Dumping Agreement provides
for flexibility in the structure of such collection sy stems, all such systems are subject to the limitation
in Article 9.3 that anti-dumping duties collected fro m the importers "shall not exceed the margin of
dumping established under Article 2", for the exporter or foreign producer concerned.
13. Fourthly, Mexico disputes the relevance to this proceeding of the Panel's findings concerning
the purported "mathematical equivalence" in the r esults that would be obtained in the absence of
zeroing under the weighted average-to-weighted average ("W-W") comparison methodology provided
for in the first sentence of Article 2.4.2 of the Anti-Dumping Agreement and the weighted average-to-
transaction ("W-T") comparison methodology provided for in the second sentence of Article 2.4.2.
The comparison methodology provided for in the second sentence of Article 2.4.2 represents an
exceptional rule that is not at issue in this disput e. Mexico points out that the Appellate Body has
consistently rejected the "mathematical equivalence" argument on the basis that it "is based on a set of
assumptions that may not hold in all situations".
31 The Appellate Body has also clarified that the
comparison methodology provided for in the second sen tence of Article 2.4.2 is an exception, and
cannot therefore determine the interpretation of the two methodologies provided for in the first
sentence of that provision. 32 Mexico further submits that the Panel improperly dismissed Mexico's
demonstration that W-T comparisons will not yield the same result as W-W comparisons if monthly
normal values are used within the targeted pattern, as foreseen under the USDOC Regulations
implementing Article 2.4.2.
33 For Mexico, there is no textual s upport for the Panel's conclusion that
Article 2.4.2 precludes the use of different averag ing periods between the W-W and W-T comparison

28Mexico's appellant's submission, para. 56 ("de valor normal prospectivo"; "los 'derechos antidumping
Estados Unidos") (quoting Panel Report, para. 7.131).
29See ibid., para. 60 (referring to Appellate Body Report, US – Zeroing (Japan), para. 162).
sistema de valor normal prospectivo puede ser distin to del 'margen de dumping' real del exportador o
pudieran no ser aplicables en todas las situaciones ") (referring to Appellate Body Report, US – Zeroing
(Japan), para. 133; and Appellate Body Report, US – Softwood Lumber V (Article 21.5 – Canada), para. 99).
32See ibid. (referring to Appellate Body Report, US – Zeroing (Japan), para. 133; and Appellate Body
Report, US – Softwood Lumber V (Article 21.5 – Canada), para. 97).
33See ibid., paras. 68 and 74.

methodologies. To the contrary, Article 2.4 of the Anti-Dumping Agreement requires the use of
shorter averaging periods in W-T comparisons, by stipulating that the comparison between export
price and normal value be made "at as nearly as possible the same time".
14. Finally, Mexico argues that the Panel imprope rly sought to justify its conclusions on the
grounds of "undesirable results"
34 that would arise from a prohibition of simple zeroing. For example,
the Panel asserted that a prohibition of simple zer oing would inappropriately "expand the scope of
periodic reviews"35 to cover all export shipments of an expor ter or foreign producer. Mexico disputes
this conclusion, arguing that the USDOC Regulations do not give investigating authorities the
discretion to limit the scope of the reviews to only exports pertaining to the importer requesting the
review. According to Mexico, importers may request the USDOC to initiate a periodic review of any
exporter or foreign producer from which they have imported during the review period. However, "if
an exporter is reviewed at all, the USDOC will examine all the export sales of that exporter or
producer."
36 Mexico also argues that, under United States law, exporters or the domestic industry
may request the initiation of a periodic review, and th at in such cases the scope of the review will not
be limited to sales made to specific importers. Mexico further dismisses as speculative the Panel's
conclusion that a prohibition of simple zeroing will conflict with the remedial purposes of anti-
dumping duties by creating a "competitive disincentive to engage in fair trade" 37 among individual
importers. Even if such considera tions were relevant to resolving this dispute, Mexico observes that,
"[t]o the extent that the anti-dumping measures impo sed are intended to create incentives for a change
in pricing behaviour ..., the party to be enc ouraged logically is the exporter or producer." 38 In
addition, Mexico argues that, whereas it is clear from the text of the Anti-Dumping Agreement that all
imports from an exporter or foreign producer found to be dumping may be included in the volume of
"dumped imports" for the purposes of determining in jury, the Panel's reasoning implies that, for
purposes of duty assessment, "the same transactions are treated as 'non-dumped' for one purpose, and
as 'dumped' for another purpose." 39 Such reasoning runs contrary to "the requirement for consistent
treatment of a product"40 in determining dumping and its injurious effect on the domestic industry.

del exportador o productor"). (original emphasis)
exportador o productor").

(b) Article 2.4 of the Anti-Dumping Agreement
15. Mexico argues that the Panel erred in finding that simple zeroing in periodic reviews is not,
as such, inconsistent with Article 2.4 of the Anti-Dumping Agreement. Mexico requests the Appellate
Body to reverse the Panel's finding and to find, in stead, that simple zeroing in periodic reviews is
inconsistent with this provision.
16. Referring to the Appellate Body's decision in US – Zeroing (Japan) , Mexico contends that
simple zeroing is "inherently biased" 41 and hence violates the requirement in Article 2.4 to make a
"fair comparison" between normal value and export price; it "artificially inflates" 42 the margin of
dumping because export prices that exceed the normal va lue are systematically ignored. Mexico also
points out that, in reaching its finding that simple zer oing in periodic reviews is not inconsistent with
Article 2.4, the Panel relied on its erroneous conclusion that simple zeroing is not, as such,
inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-
Dumping Agreement.
17. In addition, Mexico argues that the Panel failed to address certain arguments presented by
Mexico in relation to Article 2.4. In particular, Me xico faults the Panel for failing to respond to its
arguments that simple zeroing in periodic reviews "d istorts the prices of certain export transactions by
artificially reducing them, unjustifiably inflating the apparent magnitude of dumping", and that simple
zeroing "is not impartial, even-handed, or unbiased". 43 Mexico submits that, by not considering these
arguments, the Panel failed to make an objective assessment of the matter before it as required by
Article 11 of the DSU.
2. Simple Zeroing As Applied in Periodic Reviews
18. For the same reasons as those set out above, Mexi co submits that the Panel erred in finding
that simple zeroing, as applied by the USDOC in the five periodic reviews at issue in this dispute, is
not inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of the
Anti-Dumping Agreement. Mexico therefore requests the Appella te Body to reverse this finding and
to find, instead, that the United States acted in consistently with its obligations under these
provisions.44

41Mexico's appellant's submission, para. 90 ("intrínsecamente parcial").
42Ibid. ("infla de manera artificial").
43Ibid., para. 92 (" distorsiona los precios de ciertas transacciones al reducir de manera artificial e
44See ibid., paras. 93 and 94.

3. Article 11 of the DSU

19. Finally, Mexico argues that the Panel acted inconsistently with Article 11 of the DSU by
refusing to follow Appellate Body reports adopted by the DSB that address identical issues with
respect to the same party—the United States. More specifically, Mexico asserts that, by making
findings and reaching conclusions that are "identical " to those that have already been rejected or
reversed by previous Appellate Body reports adopted by the DSB, the Panel has failed to comply with
its duty under Article 11 of the DSU to assist the DSB in discharging its responsibilities under the
DSU.45
20. Mexico acknowledges that, in the WTO dispute settlement system, a panel is generally not
bound by previous Appellate Body findings or co nclusions. However, quoting the Appellate Body
Report in US – Oil Country Tubular Goods Sunset Reviews , Mexico asserts that "following the
Appellate Body's conclusions in earlier disputes is not only appropriate, but is what would be
expected from panels [...] where the issues are the same."46
21. Furthermore, Mexico emphasizes that a panel's duties under Article 11 are underpinned by
Articles 3.2 and 3.3 of the DSU, which establish th at the dispute settlement system is "a central
element in providing security and predictability to the multilateral trading system", and that the
"prompt settlement of situations", in which a Memb er considers that any benefits accruing to it are
being impaired by measures taken by another Memb er, is "essential to the effective functioning of the
WTO".47 Mexico suggests that the Panel's failure to follow established Appellate Body precedent has
forced it to appeal findings and conclusions of the Pa nel that are identical to those that have already
been overturned by the Appellate Body in previ ous disputes that involved the same measures and the
same responding party. According to Mexico, this is inconsistent with the Panel's function to assist
the DSB in discharging its responsibilities under the DSU because it interferes with the prompt
settlement of this dispute, thereby frustrating th e effective functioning of the WTO dispute settlement
system and undermining its security and predictab ility. The Panel's failure to follow previous
Appellate Body reports, if left uncorrected, w ould diminish Mexico's rights under the covered
agreements relative to other WTO Members.

45See Mexico's appellant's submission, para. 97 ("idénticas").
46Ibid. (quoting Appellate Body Report, US – Oil Country Tubular Goods Sunset Reviews, para. 188).
47See ibid., para. 95.

B. Arguments of the United States – Appellee
1. Simple Zeroing, As Such, in Periodic Reviews
(a) Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of
the Anti-Dumping Agreement
22. The United States argues that the Panel was corre ct in finding that simple zeroing in periodic
reviews is not, as such, inconsistent with Artic les VI:1 and VI:2 of the GATT 1994 and Articles 2.1
and 9.3 of the Anti-Dumping Agreement. In the United States' view, Mexico's interpretation of these
provisions contradicts, for several reasons, the ordinary meaning of the relevant treaty text.
23. First, the United States submits that the phr ase "all comparable export transactions" in the
first sentence of Article 2.4.2 of the Anti-Dumping Agreement does not provide a basis for prohibiting
zeroing in periodic reviews. According to the Unite d States, that phrase and the rationale attached to
it in previous Appellate Body reports are li mited only to zeroing in W-W comparisons in
investigations, and they do not extend to pe riodic reviews pursuant to Article 9 of the Anti-Dumping
Agreement.48
24. Secondly, the United States maintains that Me xico's claim rests largely on a series of
Appellate Body findings that "dumping" and "margins of dumping" relate "solely, and exclusively, to
the 'product' under consideration taken 'as a whole'" 49, and that dumping cannot occur with respect to
an individual transaction. According to the United States, this leads to "a broad[] prohibition on
zeroing in all contexts [in which] 'multiple comparisons' are made" 50, and expands the prohibition of
zeroing to transaction-to-transaction ("T-T") comparis ons in investigations and in periodic reviews
under Article 9 of the Anti-Dumping Agreement. Yet, according to the United States, the notion of
"product as a whole" has no textual foundation in the covered agreements.
25. The United States submits that the term "product" is used in different ways in different
contexts in different provisions, and that it does not exclusively refer to "product as a whole". The
term "product" can have either a collective meaning or an individual meaning. Article 2.6 of the
Anti-Dumping Agreement uses the term "product" in the collec tive sense; by contrast, according to
the United States, Article VII:3 of the GATT 1994—whi ch refers to "[t]he value for customs purposes
of any imported product"—"uses the term 'product' in the individual sense of the object of a particular

49Ibid., para. 40 (quoting Mexico's first written submission to the Panel, para. 171).
50Ibid.

transaction".
51 The United States main tains that neither the Anti-Dumping Agreement , nor the
GATT 1994, provides a textual basis for requiring that a margin of dumping necessarily be
established on an aggregate basis for the "product as a whole".
26. Thirdly, the United States maintains that the Appellate Body's interpretation of the term
"margin of dumping" is at odds with long-standi ng GATT/WTO practice and the ordinary meaning of
the term. The United States disagrees with the interp retation that any margins arising from individual
transactions or individual importers are not "margins of dumping" per se but, instead, represent only
inputs to be taken into account for calculating an aggregate margin of dumping for each exporter or
foreign producer.52 According to the United States, the text and the context of the agreements lend
support to a transaction-specific meaning for the term "margin of dumping".
27. The United States argues that the term "margin of dumping" forms part of "a series of special
terms that many [negotiators] ha d ... negotiated, interpreted, app lied, debated, fought over, and
discussed for years" 53 under the General Agreement on Tariffs and Trade 1947 (the "GATT 1947"),
the Kennedy Round Agreement on Implementation of Article VI of the General Agreement on Tariffs
and Trade 54 (the " Kennedy Round Anti-Dumping Code "), and the Tokyo Round Agreement on
Implementation of Article VI of the General Agreement on Tariffs and Trade 55 (the " Tokyo Round
Anti-Dumping Code"). The United States further asserts that Article VI of the GATT 1947, the Tokyo
Round Anti-Dumping Code, and GATT 1947 practice were part of the "surrounding circumstances" 56
of the Uruguay Round negotiations and that, therefore, they constitute an important interpretative tool
for ascertaining the "ordinary meaning" of the term "margin of dumping". The United States submits
that the term "margin of dumping" first appear ed in Article VI:1 of the GATT 1947, and was
subsequently incorporated into the Kennedy Round Anti-Dumping Code , the Tokyo Round Anti-
Dumping Code , the GATT 1994, and the Anti-Dumping Agreement .57 None of these agreements
referred to a requirement to aggregate the results of various price comparisons for the "product as a
whole" to arrive at a single margin of dumping. The United States maintains that, on the contrary, the
1960 Report of the Group of Experts on Anti-Dumping and Countervailing Duties 58 (the "1960 Group
of Experts Report"), the practice of GATT Members with active anti-dumping programmes, and the

52See ibid., para. 53.
53Ibid., para. 55.
54TN.64/98, 20 June 1967.
55BISD 26S/171, entered into force 1 January 1980.
56United States' appellee's submission, para. 56 (referring to Appellate Body Report, EC – Chicken
Cuts, paras. 175 and 176).
57See United States' appellee's submission, para. 57.
58GATT Second Report of the Group of Expert s, Anti-Dumping and Countervailing Duties, GATT
Document L/1141, adopted 27 May 1960, BISD 9S/194.

negotiating history of the Anti-Dumping Agreement, demonstrate that the concepts of "dumping" and
"margin of dumping" had long been understood in GATT practice as referring to individual
transactions.59 In this respect, the United States argu es that these terms had a "special meaning" 60 in
the sense of Article 31(4) of the Vienna Convention on the Law of Treaties 61 (the " Vienna
Convention").
28. In this respect, the United States makes referenc e to two pre-WTO panels established in 1991
under Article 15 of the Tokyo Round Anti-Dumping Code to consider challenges by Japan and by
Brazil to the European Communities' affirmative anti-dumping determinations in EC – Audio
Cassettes and in EEC – Cotton Yarn, respectively. In both cases, the panels found that the European
Communities' refusal to consider "negative dumping margins" arising from non-dumped sales was not
a violation of the Tokyo Round Anti-Dumping Code . The United States claims that this demonstrates
that "there was no 'common understanding' among the Contracting Parties at the time that the term
'margin of dumping' incorporated an implicit prohibition of zeroing."62
29. Fourthly, the United States disagrees with Mexico that Article 9.3 of the Anti-Dumping
Agreement requires investigating authorities to aggregate the results of all comparisons when
calculating the overall "margin of dumping" in peri odic reviews. The United States contends that
neither Article 9.3 of the Anti-Dumping Agreement, nor Article VI of the GATT 1994, speaks to the
aggregation of individual transactions in periodi c reviews or contains an explicit or implicit
prohibition of zeroing. The United States maintains that import duties are assessed on individual
entries resulting from individual transactions. Conseque ntly, the obligation set forth in Article 9.3, to
assess no more in anti-dumping duties than the margin of dumping, is applicable at the level of
individual transactions as well. The United Stat es refers to the findings of the panels in US – Zeroing
(Japan) and US – Zeroing (EC) in support of its contention that the actual liability for anti-dumping
duties accrues to individual importers that seek to en ter such goods into the market where there is an
anti-dumping order.
30. Fifthly, the United States asserts that the rele vant context speaks against Mexico's contention
that Article VI of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement bar the calculation
of duties on the basis of individual transactions. The United States finds contextual support in
Article 9.2 of the Anti-Dumping Agreement, arguing that this provision recognizes that duties can vary
on a case-by-case basis, and do not consist of broad aggregates. In the United States' view, Article 9.2

59See United States' appellee's submission, para. 64.
60Ibid., para. 56.
61Done at Vienna, 23 May 1969, 1155 UNTS 331; 8 International Legal Materials 679.

also recognizes that such duty collection applies to the imported goods and not to the exporter or
foreign producer, because it refers to the collection of duties on "imports", which necessarily
encompasses individual transactions. Furthermore, prospective normal value systems referred to in
Article 9.4(ii) of the Anti-Dumping Agreement also reflect the notion of transaction-based duty
collection.
31. The United States further argues that a prohibiti on of zeroing that applies beyond the context
of W-W comparisons in investigations would be in consistent with the principle of effective treaty
interpretation, because it would render useless and redundant the remaining text of Article 2.4.2 of the
Anti-Dumping Agreement , which provides for an alternative targeted dumping comparison
methodology. The targeted dumping methodology in the second sentence of Article 2.4.2 is a limited
exception that was designed to address situati ons where a symmetrical comparison methodology
would mask the existence of dumping.
63 Referring to the "mathematical equivalence" argument, the
United States argues that "[i]t is hard to see how th e targeted dumping provision could have 'utility' if
the only alternative methodologies that would provide it utility are, themselves, inconsistent with the
[Anti-Dumping] Agreement". 64 Therefore, in the United States' view, a prohibition of zeroing that
applies also to the targeted dumping comparison methodology "would do major violence to the text
by rendering whole textual provisions of the agreement 'inutile'".65
32. The United States maintains that, if the Appe llate Body nonetheless concludes that the
relevant legal terms of the Anti-Dumping Agreement are ambiguous, it woul d be appropriate and
consistent with Article 32 of the Vienna Convention to rely on supplementary means of interpretation,
such as the preparatory work and th e circumstances of its conclusion. 66 The United States submits
that the negotiating history of the Uruguay Round Anti-Dumping Agreement and panel reports in
dispute settlement proceedings that were underway at the time the Anti-Dumping Agreement was
negotiated shed light on the meaning of the terms and provisions at issue in the present appeal.67

63See United States' appellee's submission, para. 88.
64Ibid., para. 90.
65Ibid., para. 93.
66See ibid., para. 94.
67See ibid., paras. 94-97.

33. The United States argues that an examination of the historical background 68 of the Anti-
Dumping Agreement demonstrates that the negotiators were not able to agree on a broad prohibition
of zeroing or a requirement to aggregate individual transactions under Article 9.3. 69 According to the
United States, "[n]o consensus could be reached because despite extensive efforts by Japan, Hong
Kong, Singapore, and the Nordic Countries, their proposals were firmly opposed by the [European
Communities], the United States and Canada".
 70
34. The United States points out that its retrospective duty assessment system is designed to
ensure that an individual importer's liability reflect s the actual level of dumping involved in that
importer's transactions. Accordingly, an importe r should not have to pay duties because another
importer bought dumped goods, or escape liability b ecause another importer has not bought dumped
goods.71 The United States argues that, if, fo llowing the Appellate Body's reasoning in US – Zeroing
(EC) and US – Zeroing (Japan), "the amount of one importer's anti dumping margin must be averaged
to account for the amount by which some other tr ansaction involving an entirely different importer
was sold at above normal value, and vice versa, then an importer could be subjected to liability for
dumped imports made by another importer over whom [it] has no control."72 According to the United
States, this would also mean that "the importer who is engaged in dumped transactions would receive
a windfall, because [it] may escape antidumping duties, or have [its] liability sharply reduced through
the actions of another importer who behaved responsibly by e liminating its dumping margin." 73 The
United States further submits that Mexico's interp retation of Article 9.3 as requiring the reduction of
duty liability to account for non-dumped transactions is also inconsistent with the treatment of
equivalent situations in prospective normal value systems.74
(b) Article 2.4 of the Anti-Dumping Agreement
35. The United States requests the Appellate Body to uphold the Panel's finding that the use of
simple zeroing in periodic reviews is not inconsistent with Article 2.4 of the Anti-Dumping

68The "historical background" that the United States invokes as support for its position consists of
pre-WTO panel reports and certain proposals submitted by various delegations in the context of the negotiations
on the Anti-Dumping Agreement . For instance: Panel Report, EC – Audio Cassettes (unadopted);
Panel Report, EEC – Cotton Yarn (adopted); Communications from Japan , MTN.GNG/NG8/W/11
and MTN.GNG/NG8/W/30; Proposals by Hong Kong, China, MTN.GNG/NG8/W/51/Add. 1 and
MTN.GNG/NG8/W/46; Proposal by Singapore, MTN.GNG/NG8/W/55; and Proposal by the Nordic Countries,
MTN.GNG/NG8/W/76. (See United States' appellee's submission, paras. 114-128)
69See United States' appellee's submission, paras. 114, 126, and 128.
70Ibid., para. 128.
71See ibid., para. 101.
72Ibid., para. 102.
73Ibid.
74See ibid., para. 103.

Agreement. The United States submits that the Panel wa s correct in rejecting Mexico's claims under
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement.
The United States argues that, in doing so, the Pane l rejected the premise underlying Mexico's claim
under the "fair comparison" requirement in Article 2.4. In addition, the United States asserts that the
"fair comparison" language in Article 2.4 encompa sses only the specific requirements set forth in that
provision and does not contain a broad-ranging mandate to determine whether all dumping
calculations are "fair" or "unfair".
75
36. The United States further observes that the te rm "fair comparison" originated in the
1967 Kennedy Round Anti-Dumping Code , where the negotiators sought to clarify the use of the
various adjustments in price comparisons as those listed in Article 2.4 of the Anti-Dumping
Agreement. The United States maintains that this la nguage was incorporated with only minor
modifications into the Tokyo Round Anti-Dumping Code . Later, it was included in the Uruguay
Round Anti-Dumping Agreement as a stand-alone sentence. However, the "fair comparison"
requirement has always been understood to refer to th e various adjustments listed in Article 2.4, and
not as a freestanding obligation relati ng to all anti-dumping calculations. 76 In this context, the United
States makes reference to the findings of the panels in EC – Audio Cassettes and EEC – Cotton
Yarn.77 According to the United States, these pre-WTO panel reports demonstrate that "fair
comparison" refers only to allowances or adjustme nts to be made to calculate normal value and the
export price, and not to zeroing.78
2. Simple Zeroing As Applied in Periodic Reviews
37. The United States requests the Appellate Body to reject Mexico's "as applied" claims that
simple zeroing in the five periodic reviews at issue is inconsistent with Articles VI:1 and VI:2 of the
GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping Agreement . In the United States'
view, the Panel properly found that simple zeroing, as such, does not violate the GATT 1994 or the
Anti-Dumping Agreement . The United States points out that Mexico's "as applied" claims are
dependent upon the outcome of its appeal of the Panel's findings relating to its "as such" claims.
79

76See ibid., para. 67.
77See ibid., paras. 67 and 69.
78See ibid., paras. 109-113.
79See ibid., para. 129.

3. Article 11 of the DSU
38. The United States disagrees with Mexico that the Panel failed to fulfil its responsibilities
under Article 11 of the DSU by not adhering to previ ous Appellate Body findings. The United States
refers to the Appellate Body Report in Japan – Alcoholic Beverages II , stating that adopted reports
"are not binding, except with resp ect to resolving the particular dispute between the parties". 80 In the
case before it, the Panel "carefully considered a nd took into account the Appellate Body's previous
rulings on zeroing and explained in detail why it did not believe they should apply in this case." 81 In
the view of the United States, "treat[ing] DSB ru lings as fully binding and definitive, even in a
situation where experts have openly and cogently disagreed, would only undermine the legitimacy of
the system".82
4. Article 17.6(ii) of the Anti-Dumping Agreement
39. The United States submits that, because its approach to periodic reviews rests on a
permissible interpretation of the GATT 1994 and the Anti-Dumping Agreement, under Article 17.6(ii)
of the Anti-Dumping Agreement, the Panel was required to find this approach to be in conformity with
the United States' WTO obligations. Article 17.6(ii) was added to the Anti-Dumping Agreement in the
closing days of the Uruguay Round negotiations. This, in the United States' view, reflects the
negotiators' recognition that they had left certain issues unresolved in the Anti-Dumping Agreement
and that customary rules of interpretation of public international law would not always yield only one
permissible reading of a given provision. For the United States, the absence of a similar provision in
other WTO agreements demonstrates that WTO Members were aware that the anti-dumping text
"would pose particular challenges and in many instances would permit more than one legitimate
interpretation".83
40. The United States requests the Appellate Body to reject Mexico's claims. For the United
States, "it is plain that Mexico and others are tryi ng to get through the Appellate Body what they did
not achieve at the negotiating table in the Uruguay Round." 84 According to the United States, to read
a new obligation into Article VI of the GATT 1994 and the Anti-Dumping Agreement "would only

80United States' appellee's submission, para. 131 (quoting Appellate Body Report, Japan – Alcoholic
Beverages II, p. 14, DSR 1996:I, 97, at 108).
81Ibid., para. 131.
82Ibid., footnote 9 to para. 11.
83Ibid., para. 137.
84Ibid., para. 140.

contribute to further uncertainty and unpredictability, and further diminish the vital role of the WTO
negotiations in expanding world trade."
85
C. Arguments of the Third Participants
1. Chile
41. Chile notes that this appeal raises the critical questions of whether panels are required to
follow previously adopted Appellate Body repor ts addressing the same issue, and whether the
Appellate Body should follow its own prior inte rpretation when reviewing a panel report that
disregards that interpretation. Chile suggests th at the Appellate Body should exercise caution in
relation to Mexico's claim that the Panel violated Article 11 of the DSU by not following previous
Appellate Body findings on the same issue covered in this dispute. Chile agrees with Mexico that the
Panel's conclusions undermine the security and predic tability of the multilateral trading system and, if
upheld by the Appellate Body, would prejudice Me xico in relation to other WTO Members.
Nevertheless, the Panel's findings cannot be considered a failure to conduct an objective assessment
of the matter pursuant to Article 11 of the DSU. Ch ile stresses that the Appellate Body itself has only
suggested that it would be "a ppropriate" and is "expected" 86 that panels follow previous Appellate
Body findings, but has not found that they are bound to do so.
42. Chile also maintains that the Appellate Body should interpret Articles VI:1 and VI:2 of the
GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping Agreement in accordance with the
rules of treaty interpretation codified in the Vienna Convention . That there are previous Appellate
Body findings on zeroing, and that this issue is being addressed under the Doha Round negotiations,
are circumstances "which must be duly appreciated but must not serve as a justification for the
Appellate Body to refrain from exercising the functions assigned to it."
87
43. Finally, Chile stresses that zeroing is designed to inflate artificially margins of dumping and
to generate a finding of dumping even where no dumping exists. In Chile's view, zeroing is,
therefore, inconsistent with the "fair comparis on" requirement contained in Article 2.4 of the Anti-
Dumping Agreement.

86Chile's third participant's submission, p. 2 ("apropiado"; "se espera" que así lo hagan).

2. European Communities
44. The European Communities agrees with Mexico th at the Panel erred in finding that simple
zeroing in periodic reviews is not, as such, and as applie d in the five periodic reviews at issue in this
dispute, inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of
the Anti-Dumping Agreement . The European Communities requests the Appellate Body to reverse
these findings, and to find, instead, that simple zer oing in periodic reviews is, as such, and as applied
in the five periodic reviews at issue in this disput e, inconsistent with Articles VI:1 and VI:2 of the
GATT 1994, Articles 2.1, 2.4, 2.4.2, 9.3, and 18.4 of the Anti-Dumping Agreement, and Article XVI:4
of the WTO Agreement.
45. The European Communities maintain s that simple zeroing in periodic reviews is inconsistent
with the requirements in Article VI of the GATT 1994 and Articles 2 and 9.3 of the Anti-Dumping
Agreement to establish "dumping" and "margins of dumping" for the product as a whole. This
requirement entails that "dumping" and "margins of dumping" cannot be found to exist only for a
type, model, or category of that product, including "a 'category' of one or more relatively low priced
export transactions".88 Investigating authorities may undertake multiple comparisons of the weighted
average normal value and individual export transactions in a periodic review; however, the results of
all such multiple comparisons must be aggregated in order to establish the margin of dumping for the
product as a whole. According to the European Communities, there is no textual basis in the
Anti-Dumping Agreement for the Panel's conclusion that investigating authorities could take into
account only certain comparison results, while disr egarding others, when calculating margins of
dumping in periodic reviews. Instead, the Anti-Dumping Agreement requires that investigating
authorities establish "dumping" and "margins of dumping" for a product in all anti-dumping
proceedings, including in periodic reviews. Mo reover, the European Communities argues that
Articles 2.2.1, 2.7, 9.4, and Annex II to the Anti-Dumping Agreement suggest that, where Members
have sought to allow investigating authorities to disr egard "certain matters", "they did so by way of
express reservation."89
46. In addition, the European Communities maintains that simple zeroing in periodic reviews is
inconsistent with the "overarc hing and independent obligation" 90 in Article 2.4 of the Anti-Dumping
Agreement to make a fair comparison between export pr ice and normal value. According to the
European Communities, simple zeroing in period ic reviews contravenes the "fair comparison"

88European Communities' third participant's submission, para. 59. (emphasis omitted)
89Ibid., para. 66. (emphasis omitted)
90Ibid., para. 70.

requirement, because it precludes investigating auth orities from taking equal account of all the data
relating to normal value and export pric e, and because it is "inherently biased"
91 against exporters, as
it artificially inflates margins of dumping irrespec tive of any changes in the exporter's pricing
behaviour. The European Communities also suggest s that the use of simple zeroing in periodic
reviews could result in "unjustified and unfair discrimination" 92 between, on the one hand, exporters
subject to those proceedings and, on the other ha nd, exporters whose margin was calculated on the
basis of W-W comparisons in original investigations without zeroing.
47. Furthermore, the European Communities argues that simple zeroing in periodic reviews is
inconsistent with the second sentence of Article 2.4.2 of the Anti-Dumping Agreement. The USDOC
applies the W-T comparison methodology in periodic reviews and calculates margins of dumping
exclusively on the basis of so-called dumped tran sactions, even though the conditions set out in the
second sentence of Article 2.4.2 fo r the application of that methodology are not fulfilled. The
European Communities contests the United States' argument that the phrase "the existence of margins
of dumping during the investigation phase" limits the sc ope of application of Article 2.4.2 to original
investigations, and argues, instead, that the disci plines of Article 2.4.2 apply equally to periodic
reviews conducted under Article 9.3 of the Anti-Dumping Agreement . According to the European
Communities, the United States relies exclusivel y on contextual reasoning in support of the
proposition that "the word 'phase' must be given a m eaning that is different from the word 'period';
and that the term 'the investigation phase' must [be interpreted as referring to] the 'original'
investigation phase."
93 The European Communities suggests, instead, that the term "during the
investigation phase" in Article 2.4.2 refers to th e "existence" and not to the "establishment" of
margins of dumping. Therefore, "the [p]hrase refe rs to a distinct period in which margins of dumping
exist, i.e. an investigation period; and not ... a period of time in which margins of dumping are
established."94 In addition, the European Communities argues that the word "investigation" in
Article 2.4.2 is not synonymous with the term "an investigation to determine the existence, degree and
effect of any alleged dumping" in Article 5.1 of the Anti-Dumping Agreement. 95 Rather, the ordinary
meaning of the word "investigation" indicates "a syst ematic examination or inquiry or a careful study
of or research into a particular subject" 96; in Article 2.4.2, that particular subject is "margins of
dumping". The European Communities agrees with th e United States that "the ordinary meaning of

91European Communities' third participant's submission, para. 85.
92Ibid., para. 89.
93Ibid., para. 113. (emphasis omitted)
94Ibid., para. 120. (original emphasis)
95Ibid., para. 130.
96Ibid., para. 131.

the term 'during ... phase' ... has a temporal aspect to it, and coincides with 'a distinct period'." 97
However, according to the European Communities, th is does not support the view that "the 'distinct
period' referred to is the period of time in which th e 'margins of dumping' must be established, as the
[United States argues], as opposed to the period of ti me in which the 'margins of dumping' must have
existed".98 For these reasons, the European Commun ities concludes that the disciplines of
Article 2.4.2 apply to periodic reviews under Article 9.3 of the Anti-Dumping Agreement.
48. The European Communities also re fers to several contextual arguments in support of this
position. In the European Communities' view, th e definition of the term "margin of dumping"
contained in Article VI:2 of the GATT 1994 is of "general application in all anti-dumping
proceedings"99, including duty assessment proceedings under Article 9 of the Anti-Dumping
Agreement. Moreover, the use of the word "normally" in the first sentence of Article 2.4.2 of the
Anti-Dumping Agreement and the exceptional nature of the second sentence of Article 2.4.2 suggest
that the obligations and methodologies contained in the first sentence of Article 2.4.2 shall apply "in
most situations".100 This is further supported by the refere nce to the disciplines of Article 2.4 in the
opening sentence of Article 2.4.2. The European Communities also maintains that the reference to
Article 2 contained in Article 9.3 confirms that a margin of dumping in duty assessment proceedings
is to be established "by referen ce to the whole of Article 2". 101 The European Communities further
argues that the phrase "to determine the existence, degree and effect of alleged dumping" in
Article 5.1 of the Anti-Dumping Agreement suggests that the word "investigation" in Article 2 does
not have the special meaning attributed to it by the United States. Finally, the European Communities
suggests that the "preparatory work"
102 of the Anti-Dumping Agreement also supports this conclusion,
and that the United States has failed to demons trate that the negotiators intended the word
"investigation" in Article 2.4.2 to have a special meaning in accordance with Article 31(4) of the
Vienna Convention.103
49. In addition, the European Communities dismis ses the Panel's relian ce on the existence of
"prospective normal value" systems under Article 9.4(ii) of the Anti-Dumping Agreement as context
supporting its conclusion that simple zeroing in periodic reviews is not inconsistent with Articles VI:1
and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement. The collection

97European Communities' third participant's submission, para. 144.
98Ibid., para. 145.
99Ibid., para. 159.
100Ibid., para. 162.
101Ibid., para. 169. (emphasis omitted)
102Ibid., para. 221. The "preparatory work" the European Communities refers to is set out in detail in
ibid., paras. 222-228 and footnotes thereto.
103See ibid., paras. 212-216.

of duties on the basis of a prospective normal value under that provision corresponds to an
intermediate stage of duty collection, because importers can request a refund of duties collected on the
basis of a prospective normal value when those dut ies exceed the exporter's contemporaneous margin
of dumping.
50. In relation to the "mathematical equivalen ce" between the results of the W-W and W-T
comparison methodologies absent zeroing, the Eu ropean Communities maintains that the W-T
comparison methodology in the second sentence of Artic le 2.4.2 is an exceptional methodology with
no relevance for the interpretation of the other two methodologies provided for in the first sentence of
Article 2.4.2. Thus, according to the European Co mmunities, "something can perfectly well be fair as
a response to targeted dumping, but unfair absent targeted dumping."
104 The European Communities
also stresses that the results of these comparisons will not coincide if the universe of export
transactions taken into account in the W-T comparison methodology is limited to the targeted pattern.
The European Communities further takes issue with the Panel's concern that the prohibition of simple
zeroing in periodic reviews would create an "i ncentive to dump" and cause "administrative
inconvenience".105 The European Communities points out that it is exporters, not importers, that
engage in the practice of dumping, and any admini strative inconvenience related to the collection of
data from all importers is of no legal relevance to this dispute.
51. The European Communities argues that the Pane l erred by not following previous Appellate
Body findings on the same issues of law and legal in terpretations involved in this dispute. In so
doing, the Panel attributed to previous Appellate Bo dy findings that have been adopted by the DSB
the same legal significance as it attributed to previous panel findings that have been reversed by the
Appellate Body. This subverts the hierarchical st ructure provided in the DSU, which confers to the
Appellate Body the "final say"106 on issues of law and legal interpreta tions developed by a panel. For
the European Communities, panels are not only "exp ected" to follow Appellate Body conclusions in
earlier disputes, "especially where the issues are the same" 107, but are also " de jure "108 obliged to
follow the findings of the Appellate Body where th e Appellate Body has interpreted the same legal
questions. This is consistent with the need to provide security and predic tability to the multilateral
trading system, as well as the need for prompt settle ment of disputes. Moreover, the Panel's view on
the value of precedent defeats the object and purpose of the appeal mechanism provided in the DSU,

106Ibid., para. 39.
107Ibid., para. 33 (quoting Appellate Body Report, US – Oil Country Tubular Goods Sunset Reviews ,
para. 188). (emphasis added by the European Communities omitted)
108Ibid., para. 35.

because panels would be entitled to examine all legal issues "afresh" 109 in every dispute. The
European Communities suggests that, in performing its treaty interpretation task under the DSU, the
Appellate Body seeks to ascertain the common inte nt of all WTO Members in relation to the
provisions of the covered agreements. For this reason, the Appellate Body's interpretation
"necessarily transcends the particular facts of one case, and is not confined to the Members who are
parties to a particular dispute."
110 A rule whereby panels must follow Appellate Body findings on
legal questions would not prevent panels from depa rting from earlier decisions, provided there are
"cogent reasons"111 for doing so. In this dispute, however, such departure on the part of the Panel was
not justified, because it was grounded solely on th e Panel's disagreement with previous Appellate
Body findings. While panelists might not always ag ree with the findings of the Appellate Body on
particular legal issues, the role of the Appellate Body is "to definitively settle such disagreements over
points of law".112 Therefore, the Appellate Body should reaffirm that all panels are not only expected,
but are "obliged"113 to follow its findings in relation to the issue of zeroing.
3. Japan
52. Japan agrees with Mexico that the Panel erred in finding that simple zeroing in periodic
reviews is not, as such, and as applied in the five peri odic reviews at issue in this dispute, inconsistent
with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping
Agreement. Japan requests the Appellate Body to reve rse these findings, and to find, instead, that
simple zeroing in periodic reviews is, as such, and as applied in the five periodic reviews at issue in
this dispute, inconsistent with these provisions.
53. Japan charges the Panel with ignoring the "overarching principles" of the Anti-Dumping
Agreement, namely, that: "dumping" and "margins of dumping" are defined in relation to the
"product" as a whole; dumping determinations ar e made in respect of each exporter or foreign
producer; and the GATT 1994 and the Anti-Dumping Agreement are concerned with dumping that
causes or threatens to cause material injury to the domestic industry.
114 Japan argues that Article VI:1
of the GATT 1994 and Article 2.1 of the Anti-Dumping Agreement define "dumping" and "margins of
dumping" in relation to a "product as a whole , and not to a sub-part of the product". 115 Therefore,

109European Communities' third participant's submission, para. 42.
110Ibid., para. 46.
111Ibid., para. 50.
112Ibid., para. 55.
113Ibid., para. 56. (emphasis omitted)
114Japan's third participant's submission, para. 26.
115Ibid., para. 36 (referring to Appellate Body Report, US – Zeroing (Japan), paras. 108-110, 115, and
189). (original emphasis)

neither "dumping", nor "margins of dumping", can be found to exist at the model-specific or
transaction-specific level. Japan recognizes that the words "product as a whole" do not appear in the
text of the Anti-Dumping Agreement . However, it is clear that the concepts of "dumping" and
"margins of dumping" relate to th e pricing behaviour of exporters and foreign producers, and cannot
be established on an importer-specific basis.
116 While liability for payment of anti-dumping duties
may be calculated transaction-wise, the rate and amount of that payment, by virtue of Article 9.3 of
the Anti-Dumping Agreement , is limited to the margin of dumping calculated for the exporter or
foreign producer under Article 2. Japan further agr ees with Mexico that "the obligation to levy anti-
dumping duties only if the dumped imports cause or thr eaten to cause material injury to the domestic
industry producing the like product ... cannot be fulfilled if the investigating authorities are free to
disregard some or most of the sales comparisons for an exporter."117
54. Turning to the contextual arguments develope d by the Panel, Japan argues that the Panel
incorrectly found that the reference to the word "product" in Articles VI:6 and VII:3 of the
GATT 1994 should be read to suggest that the word "p roduct" in Article VI:1 may be interpreted on a
transaction-specific basis. Japan s ubmits that the term "product" in the context of Article VI:6 also
refers to the "product" "as a whole". Article VII: 3, in turn, deals with customs valuation of goods,
which is typically performed on a transaction- specific basis. The "significant differences" 118 in text,
context, and object and purpose of Articles VI:1 and VII:3 of the GATT 1994 imply that the words
"product" and "products" have different meanings in these provisions. In addition, Japan argues that
the existence of prospective normal value systems provided for in Article 9.4(ii) of the Anti-Dumping
Agreement does not indicate that simple zeroing in periodic reviews is permitted. While
Article 9.4(ii) permits the imposition and collecti on of dumping duties on the basis of a prospective
normal value, margins of dumping must still be es tablished in accordance with Article 2, which
prohibits zeroing.119
55. Japan further contests the Panel's conclu sion that, absent zeroing, the W-T and W-W
comparison methodologies would yield "mathematically equivalent" results and points out that the

116See Japan's third participant's submission, para. 49. Japan finds contextual support for its arguments
in Article 6.10 of the Anti-Dumping Agreement.
derechos sólo si los importaciones que incurren en dumping causan o amenazan causar daño a la rama de
exportador")).
118Ibid., para. 71.
119See ibid., para. 74.

Appellate Body has "consistently rejected" 120 the "mathematical equivalence" argument in past
appeals. Japan submits that, "all that the Panel has shown is that, in one set of circumstances , an
authority can 'permissibly' elect to develop methodol ogies that generate mathematical equivalence by
relying on identical time periods." 121 According to Japan, "[t]here is nothing novel in this position
because the Appellate Body has already acknowledge d that under certain conditions, equivalent
outcomes are possible." 122 Japan agrees with Mexico that "the United States' own anti-dumping
legislation provides for the use of ... differential ti me periods in the calculation of weighted average
normal values using the [W-W] methodology in investigations and the [W-T] methodology in
periodic reviews, thus ensuring that different outcomes will occur." 123 In addition, Japan maintains
that the W-T comparison methodology provided in the second sentence of Article 2.4.2 applies
exclusively to situations of targeted dumping, a nd cannot be determinative of the question of whether
simple zeroing in periodic reviews is permitted.
56. Japan submits that the "undesirable results" 124 the Panel considers would arise from a
prohibition of zeroing fall under "neither text, context, object, nor purpose" 125 and are therefore
irrelevant to the legal interpretation of the Anti-Dumping Agreement . Japan disagrees with the
concerns expressed by the Panel that a prohibition of simple zeroing in periodic reviews would create
a "competitive disincentive to engage in fair trade" among different importers.126 According to Japan,
authorities are not required to allocate anti-dumpi ng duties evenly among all importers of a given
exporter's merchandise. However, any allocation of anti-dumping duties is subject to the requirement
under WTO law that the total amount of duties levi ed shall not exceed the exporter's margin of
dumping. Furthermore, Japan argues that a prohib ition of simple zeroing in periodic reviews would
not, as the Panel found, expand the scope of pe riodic reviews and thus cause "administrative
inconvenience"127 to investigating authorities. Regardless of which interested party requests a
periodic review, it is the exporter that is required to provide data on all sales made to the United States
because importers do not have a "normal value". 128 Japan also argues that a prohibition of simple
zeroing in periodic reviews would not, as the Panel found, preclude anti-dumping duties from

120Japan's third participant's submission, para . 77 (referring to Appellate Body Report, US – Zeroing
(Japan), paras. 133-135; and Appellate Body Report, US – Softwood Lumber V (Article 21.5 – Canada) ,
paras. 97-100).
121Ibid., para. 90. (original emphasis)
122Ibid.
123See ibid., para. 85 and footnote 89 thereto. See also Mexico's appellant's submission, para. 83 and
footnotes 64 and 65 thereto.
125Ibid., para. 94.
128Ibid., para. 99.

removing the injurious effects of dumping. It is only by including all export transactions in a periodic
review that investigating authorities can levy dumping duties at a level no greater than that necessary
to remove the injurious effect of dumping.
57. Japan argues that the Panel erred in rejecting Me xico's claim that simple zeroing in periodic
reviews is inconsistent with Article 2.4 of the Anti-Dumping Agreement . Japan refers to previous
Appellate Body reports that have made it clear th at the use of zeroing in periodic reviews is not
"impartial, even-handed, or unbiased" and is ther efore inconsistent with the "fair comparison"
requirement contained in Article 2.4.
129
58. Finally, Japan submits that the Panel's refusal to follow previous Appellate Body reports
addressing "exactly the same measures and claims" 130 amounts to a failure to conduct an objective
assessment of the matter as required by Article 11 of the DSU. The adoption of Appellate Body
reports by the DSB creates "legitima te expectations among WTO Members" 131, and reflects a
clarification of all WTO Members' rights and obliga tions with respect to the matter addressed in those
reports. By setting aside adopted Appellate Body fi ndings on the same matter, the Panel "d[id] not
bring the required degree of objectivity to its work, substituting its subjective assessment of the matter
for one that carries the approval of the DSB." 132 In addition, Japan asserts that the Panel's assessment
of the matter compromised the objectives of the WT O dispute settlement system under Articles 3.2,
3.3, and 3.7 of the DSU, because it "introduce[d] uncertainty and unpredictability into the law,
disturbing the stability of the rules-based system" 133, and prevented the prompt resolution of this
dispute.
4. Thailand
59. Thailand agrees with Mexico that the Panel erre d in finding that simple zeroing in periodic
reviews is not inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4,
and 9.3 of the Anti-Dumping Agreement . Thailand also submits that the Panel's failure to follow
previous Appellate Body findings on the issue of zeroi ng raises systemic concerns in relation to the
functioning and credibility of the WTO dispute se ttlement system. Although strictly speaking not

129Japan's third participant's submission, paras. 108 and 109 (referring to Appellate Body Report, EC –
Bed Linen , para. 55; Appellate Body Report, US – Corrosion-Resistant Steel Sunset Review , para. 135;
Appellate Body Report, US – Softwood Lumber V (Article 21.5 – Canada), paras. 140-142; and Appellate Body
130Ibid., para. 13.
131Ibid., para. 15 (quoting Appellate Body Report, US – Shrimp (Article 21.5 – Malaysia), para. 108, in
turn quoting Appellate Body Report, Japan – Alcoholic Beverages II, p. 14, DSR 1996:I, 97, at 108). (emphasis
added by Japan omitted)
132Ibid., para. 18.
133Ibid., para. 24.

binding, previous Appellate Body findings "c reate legitimate expectations among WTO Members" 134,
and therefore panels are "expected" to follow previo us Appellate Body conclusions, "especially when
the issues are the same". 135 Thailand emphasizes that a panel's failure to observe the hierarchy
between panels and the Appellate Body, especially where the Appellate Body has repeatedly decided
on the same issue, impairs the effective functi oning of the WTO dispute settlement system, and
undermines its security and predictability. Moreover, if WTO Members cannot be reasonably
confident that the decisions of panels will be consis tent with the jurisprudence of the Appellate Body,
they "will begin to see the dispute settlement process as requiring both panel and Appellate Body
proceedings in order to obtain an objec tive assessment of the matter at issue." 136 According to
Thailand, "[t]his will increase the costs of using the system and decrease the efficiency of the system
in promptly resolving disputes between Members" 137 and discourage participation by developing
country Members.138
60. Thailand further argues that "[i]t is beyond di spute that the Appellate Body's rulings on
zeroing gave rise to legitimate expectations among Members." 139 According to Thailand, "[t]hese
legitimate expectations have been undermined by th e recent panels that have declined to follow the
Appellate Body's jurisprudence, most notably the Panel in this case." 140 Thailand submits that the
Appellate Body's findings on the zeroing issue "hav e been both clear and correct", and urges the
Appellate Body to reverse the Panel's findings on zeroing and to "clarif[y] the importance to the
credibility of the WTO dispute settlement system that panels follow unambiguous Appellate Body
rulings."141
61. Thailand further notes that, in rejecting the Ap pellate Body's interpretation that the word
"product" in Article 2.1 of the Anti-Dumping Agreement refers to the product under investigation "as a
whole", and not to a specific transaction, the Panel fa iled to consider the broader ramifications of its
interpretation. Thailand points out that, with the exception of panels that have addressed the issue of
zeroing, panels that have considered the concep t of dumping in other contexts have adopted the
interpretation that dumping must be defined in relati on to a product, and not in relation to individual
transactions. Therefore, a departure from this in terpretation would affect Members' obligations in

134Thailand's third participant's submission, para. 13 (quoting Appellate Body Report, Japan –
Alcoholic Beverages II, p. 14, DSR 1996:I, 97, at 108).
135Ibid. (quoting Appellate Body Report, US – Oil Country Tubular Goods Sunset Reviews, para. 188).
136Ibid., para. 15. (original emphasis)
137Ibid.
138See ibid.
139Ibid., para. 16.
140Ibid.
141Ibid., para. 17.

relation to other stages of dumping proceedings, such as the initiation phase, injury determination, and
the imposition of anti-dumping duties. Thailand argues that systemic concerns call for an
interpretation pursuant to which dumping is uniformly defined in relation to a product in all stages of
anti-dumping proceedings.
62. Thailand adds that, until a WTO panel or the Appellate Body decides that WTO Members
must use the same weighted average normal va lue in W-W and W-T comparisons in original
investigations, the targeted dumping provision in the second sentence of Article 2.4.2 of the Anti-
Dumping Agreement "is simply not relevant to the issue of whether zeroing is permissible"
142, and
that, therefore, the "mathematical equivalence" argument does not hold.
63. Thailand also maintains that the second sentence of Article 2.4.2 is neither at issue in this
dispute, nor determinative of whether simple ze roing in periodic reviews is consistent with
Articles 2.1 and 9.3 of the Anti-Dumping Agreement. Thailand also dismisses the Panel's suggestion
that a prohibition of zeroing would expand the scope of periodic reviews, because, in USDOC
periodic review proceedings, including those at issue in this dispute, "exporters are already required
to 'submit information pertaining to all of their e xport transactions rather than those pertaining to the
importer requesting the review.'"
143
64. Finally, Thailand rejects the Panel's assumpti on that, "even if some transactions are not
dumped, the domestic industry is injured by the dumped imports." 144 According to Thailand, "this
simply begs the question of the basis on wh ich the determination of injury was made." 145 If the
determination of injury were made only on the b asis of the effects of individual transactions, the
Panel's position might have some merit. However, the volume of dumped imports, for the purpose of
determining injury, includes both "dum ped" and "non-dumped" transactions. 146 I n t h e s e
circumstances, according to Thailand, "it makes no se nse to distinguish between the injurious effects
of individual transactions."147

142Thailand's third participant's submission, para. 35.
145Ibid.
146See ibid. (referring to Panel Report, EC – Bed Linen, paras. 6.135-6.142).
147Ibid., para. 37.

III. Issues Raised in This Appeal
65. The following issues are raised in this appeal:
(a) whether the Panel erred in finding that "s imple zeroing in periodic reviews" is not,
as such, inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1
and 9.3 of the Anti-Dumping Agreement;
(b) whether the Panel erred in finding that the United States Department of Commerce
(the "USDOC") did not act inconsistently with Articles VI:1 and VI:2 of the
GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement by using
simple zeroing in the five periodic reviews at issue in this dispute;
(c) whether the Panel erred in finding that "s imple zeroing in periodic reviews" is not,
as such, inconsistent with Article 2.4 of the Anti-Dumping Agreement and,
consequently, in finding that the USDOC did not act inconsistently with that
provision in the five periodic reviews at issue in this dispute; and
(d) whether the Panel failed to fulfil its obligations under Article 11 of the DSU by
making findings that contradict those in pr evious Appellate Body reports adopted by
the DSB.
IV. Introduction
66. The issue of "zeroing" has been raised on app eal on numerous occasions in different contexts.
The Appellate Body has examined the WTO-cons istency of the zeroing methodology in original
investigations, periodic reviews148, new shipper reviews149, and sunset reviews.150 In each context, the
Appellate Body has held that zeroing is inconsiste nt with the relevant provisions of the GATT 1994

148The term "periodic review" applies to the "periodic review of amount of anti-dumping duty" under
Section 751(a) of the United States Tariff Act of 1930 (the "Tariff Act"). That provision requires the USDOC to
review and determine the final liab ility for anti-dumping duty at least once during each 12-month period
beginning on the anniversary of the date of publication of an anti-dumping duty order, if a request for such a
review has been received. However, in the case of th e first assessment proceeding following the issuance of the
Notice of Antidumping Duty Order, the period of time may extend up to 18 months in order to cover all entries
that may have been subject to provisional measures.
149The term "new shipper review" applies to the revi ew to establish an individual weighted average
dumping margin for the exporter or foreign producer under Section 751(a)(2)(B) of the Tariff Act. That
provision requires the USDOC to review and determine the individual dumping margin for an exporter or
foreign producer that did not export the product at issue during the original period of investigation.
150The term "sunset review" applies to the review of an anti-dumping duty order at the end of five
years, as required by Section 751(c) of the Tariff Act. That provision requires the USDOC to conduct a review,
five years after the date of publication of an anti-dumping duty order, to determine whether revocation of the
anti-dumping duty order would be likely to lead to continuation or recurrence of dumping and of material injury.

and the Anti-Dumping Agreement . More specifically, the Appellate Body has found zeroing to be
inconsistent with Article 2.4.2 of the Anti-Dumping Agreement in the original investigations in five
disputes.
151 The Appellate Body has also found zeroing in periodic reviews to be inconsistent with
Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement in two disputes. 152
In one of those disputes, the Appellate Body fu rther found zeroing in new shipper reviews to be
inconsistent with Article 9.5 of the Anti-Dumping Agreement.153 Moreover, in that same dispute, the
Appellate Body found that the United States had acted inconsistently with Article 11 of the Anti-
Dumping Agreement because it relied on margins of dumping calculated in previous proceedings in
using zeroing in two sunset review determinations.154
67. Before the Panel, Mexico distinguished betw een two types of zeroing: "model zeroing in
investigations" and "simple zeroing in periodic re views". By "model zeroing in investigations",
Mexico meant the method under which the USDOC, in original investigations, makes a weighted
average-to-weighted average ("W-W") comparison of export price and normal value for each "model"
of the product under investigation, and disregards the amount by which the weighted average export
price exceeds the weighted averag e normal value for any model, when aggregating the results of
model-specific comparisons to calcu late a weighted average margin of dumping for the exporter or
foreign producer 155 investigated. 156 By "simple zeroing in periodic reviews", Mexico meant the
method under which the USDOC, in periodic reviews fo r assessment of final liability for payment of
anti-dumping duties, compares the prices of indivi dual export transactions against monthly weighted
average normal values, and disregards the amount by which the export price exceeds the monthly

151See Appellate Body Report, EC – Bed Linen , para. 66; Appellate Body Report, US – Softwood
Lumber V, para. 117; Appellate Body Report, US – Softwood Lumber V (Article 21.5 – Canada) , para. 124;
Appellate Body Report, US – Zeroing (Japan) , para. 138; and Appellate Body Report, US – Zeroing (EC) ,
para. 222. In addition, we note that model zeroing in original investigations has been found to be inconsistent
with Article 2.4.2 of the Anti-Dumping Agreement by all panels that have examined that practice, including the
panels in EC – Bed Linen , EC – Tube or Pipe Fittings , US – Softwood Lumber V , US – Zeroing (EC) ,
US – Zeroing (Japan) , and US – Shrimp (Ecuador) , as well as the Panel in this dispute. (See Panel Report,
paras. 7.55, 7.61, and 8.1(a))
152See Appellate Body Report, US – Zeroing (EC) , paras. 132-135; and Appellate Body Report, US –
Zeroing (Japan), para. 166.
153See Appellate Body Report, US – Zeroing (Japan), paras. 165 and 166.
154See ibid., paras. 185 and 186. In US – Corrosion-Resistant Steel Sunset Review, the Appellate Body
stated that it saw "no obligation under Article 11.3 [of the Anti-Dumping Agreement ] for investigating
authorities to calculate or rely on dumping margins in determining the likelihood of continuation or recurrence
of dumping". (Appellate Body Report, US – Corrosion-Resistant Steel Sunset Review , para. 127) However, if
the investigating authorities choose to rely on dumping margins in making their likelihood determination in a
sunset review, "the calculation of these margins must conform to the disciplines of Article 2.4." ( Ibid.) The
Appellate Body was, however, unable to complete the anal ysis and rule on the use of zeroing in that particular
case because it did not have a sufficient factual basis to do so. (See Ibid., paras. 133-138) See also Appellate
Body Report, US – Zeroing (Japan), paras. 165 and 166.
155In our discussion, we hereinafter use the term "expo rter(s)" to refer to exporter(s) and/or foreign
producer(s).
156See Panel Report, paras. 7.7-7.9.

weighted average normal value for each model, when aggregating the results of the comparisons to
calculate the margin of dumping for the exporte r and the duty assessment rate for the importer
concerned.157
68. The Panel agreed with Mexico that "model zeroi ng in investigations" is, as such, inconsistent
with Article 2.4.2 of the Anti-Dumping Agreement .158 As a result, the Panel found that the USDOC
also acted inconsistently with Article 2.4.2 by a pplying model zeroing in the original anti-dumping
investigation at issue in this dispute. 159 The Panel, however, rejected Mexico's claim that "simple
zeroing in periodic reviews" is, as such, inconsiste nt with Articles VI:1 and VI:2 of the GATT 1994
and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping Agreement.160 As a result, the Panel found that the
USDOC did not act inconsistently with those provisions by using simple zeroing in the five periodic
reviews at issue in this dispute.
161 In reaching this conclusion, the Panel disagreed with the
jurisprudence and conclusions of the Appellate Body in US – Zeroing (EC) and US – Zeroing (Japan).
69. Mexico appeals the Panel's findings regardi ng the WTO-consistency of simple zeroing in
periodic reviews and requests the Appellate Body to find, instead, that simple zeroing in periodic
reviews is inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of
the Anti-Dumping Agreement. In addition, Mexico claims that th e Panel acted inconsistently with its
obligations under Article 11 of the DSU by ma king findings that "directly contradict" 162 those in
adopted Appellate Body reports.
70. By contrast, the United States asserts that the Appellate Body should dismiss Mexico's
appeal. The United States requests the Appellate Body to uphold the Panel's finding that simple
zeroing in periodic reviews is allowed under Articles VI:1 and VI:2 of the GATT 1994 and
Articles 2.1, 2.4, and 9.3 of the Anti-Dumping Agreement, because it is a permissible interpretation of
these provisions in accordance with Article 17.6(ii) of the Anti-Dumping Agreement.

157See Panel Report, paras. 7.7-7.9 and 7.99.
158Ibid., para. 8.1(a). However, the Panel did not recommend to the DSB that it request the United
States to bring its model zeroing procedures into conformity with its obligations under the Anti-Dumping
Agreement and Article VI of the GATT 1994 because of its earlier finding that the United States had abandoned
that practice as from 22 February 2007. ( Ibid., para. 7.45) The Panel explaine d that it "fail[ed] to see what
purpose would be served by a recommendation relating to a measure that no longer exists." (Ibid., para. 7.50)
159Ibid., para. 8.1(b); USDOC, Notice of Final Determination of Sales at Less Than Fair Value:
Stainless Steel Sheet and St rip in Coils from Mexico, United States Federal Register, Vol. 64, No. 109 (8 June
1999) 30790, subsequently amended as Notice of Amende d Final Determination of Sales at Less Than Fair
Value and Antidumping Duty Order: Stainless Steel Sheet and Strip in Coils from Mexico, United States
Federal Register, Vol. 64, No. 143 (27 July 1999) 40560 (Exhibit MEX-5.A submitted by Mexico to the Panel).
160Panel Report, para. 8.1(c).
161Ibid., para. 8.1(d). The five periodic reviews challenged by Mexico are listed in Exhibits MEX-5.B
through MEX-5.F submitted by Mexico to the Panel; further details may be found in Panel Report, para. 2.2.
162Notification of an Appeal by Mexico, WT/DS344/7 (attached as Annex I to this Report), para. 4
("contradicen directamente").

A. The United States' System for the Imposition and Assessment of Anti-dumping Duties
71. Before addressing the issues raised by the participan ts in this appeal, we consider it useful to
provide a brief overview of the United States' system for the imposition and assessment of anti-
dumping duties. This overview is based on the explan ations provided by the participants in their
written submissions and at the oral hearing in the course of these appellate proceedings.
72. The first stage of the system is the original investigation for the imposition of anti-dumping
duties. The USDOC conducts an investigation to determine whether dumping by an exporter
occurred during the period of investigation. This is done by calculating an "overall weighted average
dumping margin for each foreign producer/exporter investigated".
163 This determin ation is published
in a Notice of Final Determination of Sales at Less Than Fair Value. The USDOC communicates its
determination of the existence and level of dumping to the United States International Trade
Commission (the "USITC"). The USITC conducts an investigation to determine whether the relevant
United States industry is materially injured or threatened with material injury by reason of the dumped
imports. If the USDOC finds that dumping existed du ring the period of investigation, and the USITC
finds that the domestic industry was materially injure d, or threatened with ma terial injury, by reason
of dumped imports, the USDOC issues a Notice of Antidumping Duty Order and imposes an
"estimated anti-dumping duty deposit rate"
164 (also referred to as a "cash deposit rate"), equivalent to
the "overall weighted average dumping margin", for each exporter individually examined. In
addition, the Notice of Antidumping Duty Order sets out an "all-others" rate applicable to exporters
that were not individually examined.
73. In order to determine the existence of dumping and the "overall weighted average dumping
margin" for each exporter investigated, the USDOC normally uses the W-W comparison methodology
under which the weighted average normal value is compared with the weighted average export
price.165 In doing so, the USDOC takes into consider ation all of the export transactions of each
exporter investigated. The Panel found, as a factua l matter, that "the United States [had] abandoned
the practice of model zeroing in inve stigations as from 22 February 2007". 166 In other words, the
USDOC currently takes into account the results of all model-specific comparisons, regardless of
whether the weighted average export price is above or below the weighted average normal value for

164Ibid., para. 17.
165The United States stated at the oral hearing that, in investigations, it "almost universally" uses the
W-W comparison methodology and that it rarely uses the transaction-to-transaction ("T-T") comparison
methodology, because the latter met hodology is a "very burdensome proced ure" and is appropriate only in
limited circumstances.
166See Panel Report, para. 7.50. This was also confirmed by the United States at the oral hearing.

each model. If the "overall weighted average dumping margin" for a particular exporter thus
calculated is zero, or below de minimis levels, that exporter is not found to be dumping and the
investigation is terminated in relation to it. On the other hand, if the "overall weighted average
dumping margin" is above de minimis levels, the exporter is found to be dumping, and the entire
volume of sales made by that exporter is considered to be "dumped imports" for purposes of the injury
determination.167
74. The second stage of the United States' system is the assessment of the final liability for anti-
dumping duties. For assessing anti-dumping duties, the United States follows a "retrospective"
assessment system under which final liability fo r anti-dumping duties is determined after the
merchandise is imported. Under this system, the United States initially collects cash deposits at the
time of each entry of the subject merchandise at th e estimated anti-dumping duty deposit rate of the
relevant exporter. Subsequently, once a year, during the anniversary month of the anti-dumping duty
order, interested parties—including importers, domes tic interested parties, foreign producers, and
exporters
168—may request the USDOC to conduct a periodic review to determine the final amount of
anti-dumping duties owed on entries that occurred during the previous year. If a request for a periodic
review is made by any party, the USDOC will review all sales made by the relevant exporter in order
to calculate a going-forward cash deposit rate that will apply to all future entries of the subject
merchandise from that exporter. Simultaneously, the USDOC will calculate a duty assessment rate
applicable to each importer that imports from th at exporter and determine the final liability for
payment of anti-dumping duties by that importer on the basis of its duty assessment rate. If no
periodic review is requested, the cash deposits made on entries during the previous year are
automatically assessed as the final duties.
75. In a periodic review, the USDOC determines th e final liability for anti-dumping duties of an
individual importer—that is, the duty assessment rate applicable to that importer—on the basis of a
methodology that compares monthly weighted average normal value with prices of individual export
transactions.169 Under this methodology, the product under consideration is broken down into models,
and a monthly weighted average normal value is determined for each model. 170 When comparing the
monthly weighted average normal value with the price of each individual export transaction, the
USDOC considers the amount by which the normal value exceeds the export price to be the "dumping

167United States' response to questioning at the oral hearing.
168See Panel Report, footnote 74 to para. 7.98. See also United States' appellee's submission, para. 21;
and USDOC Regulations, Section 351.213(b).
169See supra, para. 67. See also USDOC Regulations, Section 351.414(c)(2); and USDOC
Antidumping Manual, chapter 6, p. 7.
170See Panel Report, para. 7.99.

margin" for that export transaction.
171 If, however, the export price exceeds the normal value, the
USDOC considers the "dumping margin" for that export transaction to be zero. For each importer,
the USDOC expresses the total of the "dumping margins" as a percentage of the total entered value of
its imports of the subject merchandise from the re levant exporter, including the value of those
transactions for which the dumping margin was considered to be zero. 172 This percentage becomes
the "duty assessment rate" for that importer, and it is applied to the total entered value of its imports
from the relevant exporter during the period review ed in order to determine the final anti-dumping
liability of that importer. The same zeroing me thodology is also applied to determine the going-
forward cash deposit rate for all future entr ies of the subject merchandise from the exporter
concerned.
B. Standard of Review: Article 11 of the DSU and Article 17.6 of the Anti-Dumping
Agreement
76. Before turning to the issues raised on appeal, we recall that the standard of review applicable
to disputes under the Anti-Dumping Agreement is set out in both Article 11 of the DSU and
Article 17.6 of the Anti-Dumping Agreement .173 As regards issues of legal interpretation,
Article 17.6(ii) provides that:
[a] panel shall interpret the releva nt provisions of the Agreement in
accordance with customary rules of interpretation of public
international law. Where the panel finds that a relevant provision of
the Agreement admits of more than one permissible interpretation,
the panel shall find the authorities' me asure to be in conformity with
the Agreement if it rests upon one of those permissible
interpretations.
The Appellate Body has noted that the customary rul es of interpretation of public international law as
codified in Articles 31 and 32 of the Vienna Convention apply to the interpretation of the Anti-
Dumping Agreement .
174 The Appellate Body has recognized that the second sentence of
Article 17.6(ii):

171See Tariff Act, Section 751(a)(2)(A)(ii).
172See USDOC Regulations, Section 351.212(b)(1). See also Panel Report, para. 7.99: "The numerator
for the importer-specific assessment rate reflects the re sults of comparisons where the normal value exceeds the
export price within the universe of the imports made by that particular importer, and the denominator is the total
value of all imports by the importer."
173See Appellate Body Report, US – Hot-Rolled Steel, para. 62.
174See ibid., para. 59; Appellate Body Report, EC – Bed Linen (Article 21.5 – India) , para. 118; and
Appellate Body Report, US – Softwood Lumber V, para. 116.

… presupposes that application of the rules of treaty interpretation in
Articles 31 and 32 of the Vienna Convention could give rise to, at
least, two interpretations of some provisions of the Anti-Dumping
Agreement, which, under that Convention, would both be
"permissible interpretations". In that event, a measure is deemed to
be in conformity with the Anti-Dumping Agreement "if it rests upon
one of those permissible interpretations."175 (original emphasis)
In our analysis, we therefore bear in mind that ther e could be more than one permissible interpretation
of a provision of the Anti-Dumping Agreement.
V. Simple Zeroing, As Such, in Periodic Reviews
77. The Panel found that "simple zeroing in periodic reviews" is not, as such, inconsistent with
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement.176
The Panel reasoned that Articles VI:1 and VI :2 of the GATT 1994 and Article 2.1 of the Anti-
Dumping Agreement do not "compel a definition of 'dumping' based on an aggregation of all export
transactions"177 and that those provisions do not "exclude an interpretation that allows the concept of
dumping to exist on a transaction-specific basis". 178 The Panel further reasoned that anti-dumping
duties are paid by importers and that, therefore, th e importer- or transaction-specific character of the
payment of anti-dumping duties must be taken into consideration in interpre ting Article 9.3 of the
Anti-Dumping Agreement.179 The Panel emphasized that "an importer does not incur liability for the
payment of anti-dumping duties on the basis of the totality of exports made by an exporter"180 and that
Articles 9.3.1 and 9.3.2 must be interpreted in th is light "because the former concerns the calculation
of the final liability of individual importers (in the case of a retrospective system), and the latter the
refund of duties paid in excess of the margin of dumping of individual importers (in the case of a
prospective system)." 181 For the Panel, "[t]he fact that final duties or refunds in duty assessment
proceedings are calculated for individual importers ... leads to the conclusion that Article 9.3 does not
exclude an importer and import-specific calculation [of margin of dumping], and does not necessarily
require a calculation on the basis of all sales made by an exporter." 182 The Panel considered that "the
fact that other importers do not dump, or dump at a lower margin, does not affect the liability of an

175Appellate Body Report, US – Hot-Rolled Steel, para. 59.
176Panel Report, paras. 7.143 and 8.1(c).
177Ibid., para. 7.117.
178Ibid., para. 7.119.
179See ibid., para. 7.124.
180Ibid., para. 7.126.
181Ibid. (original underlining) The Anti-Dumping Agreement gives WTO Members the discretion to
assess duties either retrospectively or prospectively.
182Ibid.

importer who imports at dumped prices".
183 The Panel expressed its concern that, "[i]f ... the
authorities have to take into account the export prices paid by other importers importing from the
same exporter or foreign producer, … importers with high margins of dumping would be favoured at
the expense of importers who do not dump or who dump at a lower margin." 184 In essence, the Panel
adopted an importer- and transaction-specific approach to the concepts of "dumping" and "margin of
dumping" and concluded that simple zeroing in periodic reviews is not, as such, inconsistent with
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement.185
78. Mexico challenges this legal interpretation by the Panel. Mexico argues that, once the
investigating authorities define the product under consideration, the scope of that definition
determines the scope of the authorities' dumping dete rmination. Therefore, dumping cannot exist in
relation to a specific type, model, or cate gory of the product under consideration, "or in relation to
individual import transactions ".186 Instead, in any anti-dumping proceeding—including periodic
reviews under Article 9.3 of the Anti-Dumping Agreement —"the margin of dumping must be
calculated in respect of the individual exporters or foreign producers subject to such proceeding and
for the product under consideration taken as a whole" 187, without disregarding any export transaction.
According to Mexico, this interpretation is consistent with the "necessary relationship" 188 between
dumping and injury, and with the fact that the purpose of anti-dumping duties is to offset dumping
and injury to the domestic industry caused by exporte rs. Mexico emphasizes that the Panel's analysis
is based on the erroneous assumption that importers have margins of dumping and that such margins
can be calculated for each individual transaction. Ac cording to Mexico, "[i]mporters may, of course,
purchase products that are priced below normal va lue ... but there is no such thing under the WTO
agreements as 'importers with high margins of dumping'".
189
79. Chile, the European Communities, Japan, and Thailand support Mexico's appeal and submit
that the Appellate Body should find that simple zer oing in periodic reviews is, as such, inconsistent
with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping

183Panel Report, para. 7.131.
184Ibid., para. 7.146.
185Ibid., para. 8.1(c).
186Mexico's appellant's submission, para. 31 (" o en relación con transa cciones individuales de
importación"). (emphasis added)
productores extranjeros sujetos a dicho procedimiento y para el producto objeto a consideración tomado en su
conjunto") (referring to Appellate Body Report, US – Zeroing (Japan), para. 156).
188Ibid., para. 46 ("relación necesaria").
importadores con altos márgenes de dumping' ").

Agreement.190 The thrust of their arguments is that these provisions establish a requirement that
"dumping" and "margins of dumping" be established by reference to a product under consideration as
a whole and to individual exporters, and not in rela tion to specific models or subsets of low-priced
transactions. They also argue that there must be a consistent treatment of dumping and margins of
dumping for all purposes and stages of anti-dumping proceedings, including injury determinations, as
these terms have the same meaning throughout the Anti-Dumping Agreement.
80. By contrast, the United States argues that th e findings of the Panel should be upheld.
According to the United States, Article VI of the GATT 1994 and Article 2.1 of the Anti-Dumping
Agreement do not require that margins of dumping necessarily be established on an aggregate basis
for the "product as a whole".
191 Rather, for the United States, "dumping" can be found to exist each
time that a weighted average normal value exceeds th e export price in a particular export transaction,
and "margins of dumping" can be calcu lated for individual import transactions. 192 The United States
argues that Article 9.3 deals with only transaction- specific comparisons, and that it does not require
the aggregation of the results of such comparisons in order to determine a margin of dumping for the
relevant exporter. The United States submits that, once an anti-dumping investigation has been
completed and an anti-dumping duty has been impos ed, in all systems, "the focus in the duty
assessment phase then shifts to individual import transactions" 193, because duties are assessed on
individual import transactions. Thus, under its retr ospective assessment system, final liability for
payment of anti-dumping duties by each importer is determined on the basis of a comparison of a
contemporaneous monthly weighted average normal value with the export price in each individual
import transaction. At the oral hearing, the United States acknowledged that the USDOC aggregates
the results of transaction-specific comparisons in periodic reviews, but explained that such
aggregation is not done for the purpose of establi shing a margin of dumping under Article 9.3.
Rather, it is done in order to determine the going-fo rward cash deposit rate for future entries of the
subject merchandise from a given exporter and, for the sake of practical convenience, to determine the
importer-specific duty assessment rate applicable to all sales made to a particular importer. The
United States further explained that, under its re trospective assessment system, neither the cash
deposit rate of an exporter, nor the duty assessment rate of an importer, constitutes a "margin of
dumping" within the meaning of Article 9.3 of the Anti-Dumping Agreement. Under its system, the
"dumping margin" calculated for each individual import transaction is the "margin of dumping"
envisaged under Article 9.3 of the Anti-Dumping Agreement. According to the United States, there

190Chile's third participant's submission, p. 2; Eu ropean Communities' third participant's submission,
192United States' response to questioning at the oral hearing.

can be multiple "margins of dumping" for each import er. Moreover, at the oral hearing, the United
States suggested that the terms "dumping" and "d umping margin" may have different meanings in
different parts of the Anti-Dumping Agreement , and that a major flaw in previous Appellate Body
jurisprudence is the interpretation that these term s have the same unitary meaning throughout the
Anti-Dumping Agreement.
194
81. The United States finds contextual support for its position in the text of Article VI:1 of the
GATT 1994. Since this Article uses the plural "produ cts" when it refers to "injurious dumping" and
the singular "product" when it refers to "dumping" , it suggests that dumping can be found at the level
of individual export transactions.195 The United States points out that, in the context of the GATT,
the concept of dumping has historically been unders tood to be applicable at the level of individual
export transactions.196
82. In our view, the reasoning of the Panel and the arguments advanced in this appeal raise,
in essence, three questions for our consideration. First, are the terms "dumping" and "margin of
dumping" exporter- or importer-re lated concepts for the purpose of Article 9.3 of the Anti-Dumping
Agreement? Secondly, can "dumping" and "margin of dum ping" be found to exist at the transaction-
and importer-specific level for the purpose of Article 9.3 of the Anti-Dumping Agreement? Thirdly, in
duty assessment proceedings under Article 9.3 of the Anti-Dumping Agreement , is it permissible to
disregard the amount by which the export price ex ceeds the normal value in any export transaction?
We examine these questions in turn below, recognizing that they are interconnected.
A. Are "Dumping" and "Margin of Dumping" Exporter- or Importer-related Concepts?
83. We begin with an examination of the concep ts of "dumping" and "margin of dumping"
under Article VI of the GATT 1994 and the Anti-Dumping Agreement . "Dumping" is defined in
Article VI:1 of the GATT 1994 as occurring when a product of one country is introduced into the
commerce of another country at less than its normal va lue. Article VI:1 further states that dumping is
to be "condemned" if it causes or threatens to cause material injury to the domestic industry producing
a like product. In turn, Article VI:2 lays down th at, "[i]n order to offset or prevent dumping, a
Member may levy on any dumped product an anti-dumping duty not greater in amount than the
margin of dumping in respect of such product." Article VI:6(a) also stipulates that no anti-dumping
duty shall be levied unless the importing Member "determines that the effect of the dumping ... is such

194United States' response to questioning at the oral hearing.
195See United States' appellee's submission, para. 52.
196See ibid., para. 58.

as to cause or threaten material injury to an esta blished domestic industry, or is such as to retard
materially the establishment of a domestic industry."
84. This definition of "dumping" is carried over into the Anti-Dumping Agreement by Article 2.1,
which states that a product is to be considered as being "dumped" if the "export price" of the product
"exported" from one country to another is less than the comparable price for the "like" product when
destined for consumption in the "exporting" count ry. Furthermore, and significantly, the opening
phrase of Article 2.1—"For the purpose of this Ag reement"—makes it clear that this definition of
"dumping" applies throughout the Anti-Dumping Agreement.197
85. The term "margin of dumping" is defined in Article VI:2 of the GATT 1994 as the difference
between the "export price" and the "normal value" (t hat is, "the domestic price" of the like product in
the exporting country) determined in accordance with Ar ticle VI:1. Article VI:2 further clarifies that
the "margin of dumping" is in respect of the dumped "product". The "margin of dumping" thus
measures the "degree"—as used in Article 5.1 of the Anti-Dumping Agreement —or the
"magnitude"—as used in Article 3.4 of the Anti-Dumping Agreement —of dumping. 198 As the
"margin of dumping" is only a measure of dumping, it also has the same meaning throughout the Anti-
Dumping Agreement by virtue of Article 2.1.
86. The elements of the definition of "dumping" c ontained in Article VI:1 of the GATT 1994 and
Article 2.1 of the Anti-Dumping Agreement —namely, that "dumping" occurs when a product is
"introduced into the commerce of another country " at an " export price " that is less than the
"comparable price for the like product in the exporting country"199—suggest to us that Article VI:1 of
the GATT 1994 and Article 2.1 of the Anti-Dumping Agreement address the pricing practice of an
exporter. Article 2.2 of the Anti-Dumping Agreement as well as Article VI:1(b) of the GATT 1994
also point in the same direction because they indi cate that, if sales of the like product in the domestic
market of the exporting country do not permit a proper comparison, the comparison may be made
with the price at which the product is exported to an appropriate third country. Similarly, Article 2.3
of the Anti-Dumping Agreement allows the "export price" to be c onstructed in cases where it appears
to the authorities that the export price is unreliable.
87. The context found in various other provisions of the Anti-Dumping Agreement confirms that
"dumping" and "margin of dumping" are exporter-speci fic concepts. Articles 5.2(ii), 6.1.1, and 6.7
indicate that the focus of an anti-dumping investig ation to determine the existence and degree of

197See Appellate Body Report, US – Zeroing (Japan), para. 109.
198See ibid., para. 110.
199Emphasis added.

dumping is the known exporters of the product under inv estigation. Furthermore, Article 5.8 provides
that there shall be "immediate termination" of an anti-dumping investigation against an exporter
where the authorities determine that the ma rgin of dumping of that exporter is de minimis, that is, if
the margin is less than 2 per cent, expressed as a percentage of the export price. A plain reading of
Article 5.8 indicates that the term "margin of dumping" as used in that provision refers to a single
margin established for each exporter by aggregation of its export transactions. The same Article
provides that, if the volume of exports originating from an exporting country is "negligible"
according to the criteria stated therein, the anti-dum ping investigation against that country must be
terminated.
88. Articles 6.10 and 9.5 of the Anti-Dumping Agreement also reveal that "dumping" and
"margin of dumping" are exporter-spe cific concepts. Thus, the first sentence of Article 6.10 requires,
"as a rule", that authorities determine "an individual margin of dumping for each known exporter or
producer concerned of the product under investigation".
200 Similar language appears in Article 6.10.2,
which provides that, in cases where the authorities have limited their examination in accordance with
Article 6.10, "they shall nevertheless determine an individual margin of dumping for any exporter or
producer not initially selected who su bmits the necessary information in time for that information to
be considered during the course of the investigation". Likewise, Article 9.5, dealing with new shipper
reviews, requires the authorities to determine an i ndividual margin of dumping for any exporter that
had not exported the product during the period of investigation.
89. There is nothing in Articles 5.8, 6.10, and 9.5 of the Anti-Dumping Agreement to suggest
that it is permissible to interpret the term "margi n of dumping" under those provisions as referring to
multiple "dumping margins" occurring at the level of individual importers. Instead, these provisions
reinforce the notion that a single margin of dumpi ng is to be established for each individual exporter
investigated.
90. Other provisions of the Anti-Dumping Agreement also confirm that "dumping" and "margin of
dumping" are exporter-specific concepts. Article 8.1 refers to the "receipt of satisfactory voluntary
undertakings from any exporter to revise its prices or to cease exports to the area in question at

200We recall that, in accordance with the rules of treat y interpretation codified in Article 33(3) of the
Vienna Convention, the terms of a treaty authenticated in more than one language "are presumed to have the
same meaning in each authentic text". It follows that the treaty interprete r should seek the meaning that gives
effect, simultaneously, to the terms of the treaty as they are used in each authentic language. We find support
for our reading in the French version of Article 6.10 of the Anti-Dumping Agreement , which requires the
determination of " une marge de dumping individuelle ", that is, "one" single margin of dumping, for "each
exporter" for "the product" under investigation. Similarl y, the Spanish version requires the determination of a
single margin ("el margen") for each exporter, not multiple margins ("márgenes").

dumped prices so that the authorities are satisfied that the injurious effect of the dumping is
eliminated."201 Article 8.2 enjoins that price undertakings "shall not be sought or accepted from
exporters unless the authorities of the importing country have made a preliminary affirmative
determination of dumping and injury caused by such dumping." 202 In addition, Article 8.5 indicates
that "[p]rice undertakings may be suggested by the authorities of the importing Member, but no
exporter shall be forced to enter into such undertakings." 203 Article 8.1 further requires that, when
price undertakings are taken, price increases thereunder shall not be higher than necessary to eliminate
the margin of dumping. Since price undertakings ar e taken from individual exporters, this also shows
that the margin of dumping is related to individual exporters.
91. We further note that Article 9.4 and subparagraph (i) of the Anti-Dumping Agreement lays
down that, "[w]hen the authorities have limited their examination in accordance with the second
sentence of paragraph 10 of Article 6, an y anti-dumping duty applied to imports from exporters or
producers not included in the examination shall not ex ceed … the weighted average dumping margin
established with respect to the selected exporters or producers".204 Where the liability for payment of
anti-dumping duties is calculated on the basis of a pr ospective normal value, Article 9.4(ii) specifies
that any anti-dumping duty applie d to such imports shall not exceed "the difference between the
weighted average normal value of the selected exporters or producers and the export prices of
exporters or producers not individually examined."205
92. We note, moreover, that Article VI of the GATT 1994 and the Anti-Dumping Agreement deal
not with dumping per se, but with dumping that causes or threat ens to cause material injury to the
domestic industry producing a "like" product.206 Indeed, the very purpose of an anti-dumping duty, at
a level not higher than the margin of dumping of each exporter, is to counteract the injury caused to
the domestic industry by dumping. Article 3.1 of the Anti-Dumping Agreement stipulates that a
determination of injury shall be based on an objective examination of both the volume of the dumped
imports and the effect of the dumped imports on prices in the domestic market for like products, and
of the consequent impact of the dumped imports on domestic producers of such like products.

201Emphasis added.
202Emphasis added.
203Emphasis added.
204Emphasis added.
205Emphasis added.
206In this regard, Article VI:1 of the GATT 1994 its elf states that dumping "is to be condemned if it
causes or threatens material injury to an established industry in the territory of a Member or materially retards
the establishment of a domestic industry". Articles 5.2 and 5.6 of the Anti-Dumping Agreement also show that
an anti-dumping investigation can be initiated or can proc eed only if the investigating authorities have evidence
of dumping, injury, and a causal link between the two.

Furthermore, Article 3.5 lays down that "[t]he authorities shall also examine any known factors other
than the dumped imports which at the same time are injuring the domestic industry and the injuries
caused by these other factors must not be attributed to dumped imports." Among such non-attribution
factors listed in this Article are "the volume and prices of imports not sold at dumping prices".
Furthermore, Article 9.1 exhorts levy of anti-dumpi ng duty at less than the full margin of dumping if
such lesser duty would be adequate to remove the injury to the domestic industry.
93. The review provisions contained under Article 11 of the Anti-Dumping Agreement also reveal
the crucial link between dumping and injury. Article 11.1 sets out the overarching principle that "[a]n
anti-dumping duty shall remain in force only as long as and to the extent necessary to counteract
dumping which is causing injury." Article 11.2 allo ws a request for review to examine whether the
injury would continue or recur if the duty were removed or varied. Article 11.3 requires an
examination as to whether the expiry of the duty woul d be likely to lead to continuation or recurrence
of dumping and injury.
94. To sum up the above analysis, it is clear fro m Articles VI:1 and VI:2 of the GATT 1994 and
the various provisions of the Anti-Dumping Agreement that: (a) "dumping" and "margin of dumping"
are exporter-specific concepts; "dumping" is prod uct-related as well, in the sense that an anti-
dumping duty is a levy in respect of the product that is investigated and found to be dumped;
(b) "dumping" and "margin of dumping" have the same meaning throughout the Anti-Dumping
Agreement; (c) an individual margin of dumping is to be established for each investigated exporter,
and the amount of anti-dumping duty levied in respect of an exporter shall not exceed its margin of
dumping
207; and (d) the purpose of an anti-dumping duty is to counteract "injurious dumping" and not
"dumping" per se. It must be stressed that, under the Anti-Dumping Agreement , the concepts of
"dumping", "injury", and "margin of dumping" are in terlinked and that, therefore, these terms should

207This does not mean that anti-dumping duties are levied upon or collected from exporters. The duties
may be levied upon or collected from the importers, but, under Article 9.3, the margin of dumping established
for an exporter operates as the ceiling for such levy and collection of duties from the importers who import from
that exporter.

be considered and interpreted in a coherent and consistent manner for all parts of the Anti-Dumping
Agreement.208
95. Based on the above analysis, we disagree with the proposition that importers "dump" and can
have "margins of dumping".209 Dumping arises from the pricing practices of exporters as both normal
values and export prices reflect their pricing strategies in home and foreign markets. 210 The fact that
"dumping" and "margin of dumping" ar e exporter-specific concepts under the Anti-Dumping
Agreement is not altered by the fact that the export pr ice may be the result of negotiation between the

208It is well recognized in international economic a nd trade literature that "dumping" is "international
price discrimination" reflecting the pricing practice of an exporting firm to charge a lower price for exported
goods than it does for the same goods sold domestically. Some examples of the definition of "dumping" in
international economic literature are as follows: "The most common form of price discrimination in
international trade is dumping, a pricing practice in which a firm charges a lower price for exported goods than
it does for the same goods sold domestically." (Paul R. Krugman and Maurice Obstfeld, International
Economics: Theory and Policy , 6th edn (Pearson Education, 2007), p. 174); "Dumping is international price
discrimination in which an exporting firm sells at a lower price in a foreign market than it charges in other
(usually its home-country) markets." (Peter H. Lindert and Thomas A. Pugel, International Economics, 10th edn
(Irwin, 1996), p. 174); "dumping: In international trade, the practice of selling a commodity at a lower price in
the export market than in the domestic market for reasons unrelated to differences in costs of servicing the two
markets" and "Dumping is a form of price discrimination studied in the theory of monopoly." (Richard G.
Lipsey, Paul N. Courant, and Christopher T.S. Ragan, Economics, 12th edn (Addison-Wesley, 1999), p. G-5 and
p. 788); "Broadly defined, "dumping" is international price discrimination. Dumping occurs when an exporter
sells merchandise in an importing country at a price below that at which it sells like merchandise in its home
country ... . A more restrictive definition of "dumping" is that it occurs when an exporter sells merchandise in
an importing country at below the cost of production of that exporter." (Raj Bhala, Modern GATT Law: A
Treatise on the General Agreem ent on Tariffs and Trade, International Trade Law Series (Sweet & Maxwell,
2005), p. 685) See also Martyn Taylor, International Competition Law: A New Dimension for the WTO?
(Cambridge University Press, 2006), pp. 264 ff.
209See Panel Report, para. 7.146.
210As the Appellate Body has previously explained: "The concept of dumping relates to the pricing
behaviour of exporters or foreign producers; it is the exporter, not the importer, that engages in practices that
result in situations of dumping." (Appellate Body Report, US – Zeroing (Japan) , para. 156 (referring to
Appellate Body Report, US – Zeroing (EC), para. 129))
In this regard, we note that the United States' St atement of Administrative Action (the "SAA") states
that, if foreign "companies continue to dump with the discipline of an order in place, it is reasonable to assume
that dumping would continue if the discipline were removed", and that, "[i]f imports cease after the order is
issued, it is reasonable to assume that the exporters could not sell in the United States without dumping and that,
to reenter the U.S. market, they would have to resu me dumping." (Uruguay Round Agreements Act, Statement
of Administrative Action, H.R. Doc. No. 103-316 (1994), reprinted in 1994 USCAAN 3773, 4040 (Public Law
No. 103-465, 108 Stat. 4809 (1994), United States Code , Title 19, Section 3501, pp. 889-890) (emphasis
added)) The SAA furt her provides that "declining import volumes accompanied by the continued existence of
dumping margins after the issuance of an order may provide a strong indication that, absent an order, dumping
would be likely to continue, because the evidence would indicate that the exporter needs to dump to sell at pre-
order volumes." (Ibid. (emphasis added)) In addition, the SAA states that "[d]eclining (or no) dumping margins
accompanied by steady or increas ing imports may indicate that foreign companies do not have to dump to
maintain market share in the United States". ( Ibid. (emphasis added)) These passages are quoted in Sections
II.A.3 and II.A.4 of the USDOC's Policies Regarding the Conduct of Five-Year ("Sunset") Reviews of
Antidumping and Countervailing Duty Orders; Policy Bulletin, United States Federal Register, Vol. 63, No. 73
(16 April 1998) 18871 and 18872) As we see it, these and other similar passages in the SAA support the notion
that "dumping" is an exporter-related concept, and that dumping reflects the pricing behaviour of exporters.

importer and the exporter.
211 Nor is it altered by the fact that it is the importer that incurs the liability
to pay anti-dumping duties.212
96. We also disagree with the proposition that the term "margin of dumping" has a different or
special meaning in the context of Article 9.3 of the Anti-Dumping Agreement. As we stated earlier, a
margin of dumping measures only the degree or magnit ude of dumping. Article 9.3 refers to the
margin of dumping as established in Article 2 of the Anti-Dumping Agreement . Article 2.1 of the
Anti-Dumping Agreement defines "dumping", and the opening phrase of that Article makes it clear
that the definition applies "[f]or the purpose of this Agreement". Therefore, "dumping" and "margin
of dumping" have the same meaning throughout the Anti-Dumping Agreement. Article 9.3 does not
indicate, either expressly or by implication, that "margin of dumping" has a different meaning in the
context of duty assessment proceedings than it does u nder Article 2. Nor does any other provision of
the Anti-Dumping Agreement suggest a special or particular meaning for this term for any stated
purpose.
213 Although transaction-based multiple comparisons may be necessary in periodic reviews
to calculate an importer's liability for payment of anti-dumping duties, this cannot impart a different
or special meaning to the term "margin of dumping" in Article 9.3.
B. Can "Dumping" and "Margin of Dumping" Be Found to Exist at the Level of a
Transaction?
97. We turn next to address the question of whethe r "dumping" and "margin of dumping" can be
found to exist at the transaction- and importer-sp ecific level for the purpose of Article 9.3 of the Anti-
Dumping Agreement.
98. First, as we noted earlier, dumping arises from the pricing behaviour of an exporter. A proper
determination as to whether an exporter is dumpi ng or not can only be made on the basis of an
examination of the exporter's pricing behaviour as re flected in all of its transactions over a period of
time. Contrary to what the Panel indicates 214, the notion that "a product is introduced into the
commerce of another country at less than its norm al value" in Article VI:1 of the GATT 1994
suggests to us that the determination of dumping with respect to an exporter is properly made not at
the level of individual export transactions, but on th e basis of the totality of an exporter's transactions

211See United States' appellee's submission, para. 99.
213See Appellate Body Report, US – Zeroing (Japan), para. 114.
214See Panel Report, para. 7.117.

of the subject merchandise over the period of investigation.215 Furthermore, as we emphasized earlier,
the Anti-Dumping Agreement deals with "injurious dumping", and the very purpose of an anti-
dumping duty is to counteract the injury caused or threatened to be caused by "dumped imports" to
the domestic industry. The notion that dumping and margin of dumping can exist at the level of an
individual transaction runs counter to these basic principles of the Anti-Dumping Agreement.216
99. Secondly, if it were permissible to determine a separate margin of dumping for each
individual transaction, several margins of dumping would exist for each exporter and for the product
under consideration.217 However, the existence of "dumping" and several "margins of dumping" at
the transaction-specific level cannot be reconciled with a proper interpreta tion and application of
several provisions of the Anti-Dumping Agreement . We do not see how, for example: the
determination of injury under Article 3; the est ablishment of an individual margin of dumping for
each exporter under Articles 5.8, 6.10, 6.10.2, 9.4, and 9.5; the acceptance of voluntary undertakings
from an exporter under Article 8; and a review under Article 11.2 or 11.3 for continuation or
revocation of an anti-dumping duty order, can be done at the transaction- or importer-specific level.
The Panel's interpretation appears to us to be prem ised on the notion that the concept of transaction-
and importer-specific dumping and margin of dumpi ng could be confined to the stage of duty
assessment and collection under Article 9.3. However, we find no textual or contextual basis for such
an interpretation.
C. Is It Permissible to Disregard the Amount By Which the Expor t Price Exceeds the
Normal Value?
100. We now turn to the question whether it is permissible, in duty assessment proceedings under
Article 9.3 of the Anti-Dumping Agreement , to disregard the amount by which the export price
exceeds the normal value in any transaction; in othe r words, whether it is permissible to use "simple
zeroing" in duty assessment proceedings.

215We note that the 1960 Group of Experts Report, to which the United States re ferred in its appellee's
submission, suggests that, in order to fulfil the principles that imposition of anti-dumping duties is justified only
where "a product was in fact found to be dumped" and where material injury is thereby caused to a domestic
industry, " the ideal method ... was to make a determination in respect of ... each single importation of the
product concerned". (Supra, footnote 58, para. 8 (emphasis added)) Such a method would avoid the need of
aggregation. The Group of Experts, itself, recognized that "[t]his however, was clearly impracticable,
particularly as regards injury ". (Ibid. (emphasis added)) Such a method of anti-dumping determination is not
before us in this appeal, nor has it been referred to by the participants or third par ticipants in these appellate
proceedings.
216We are not dealing here with a hypothetical case where there may be just one large import
transaction at a price below normal value, which, by itself, is causing injury to the domestic industry.
217See also Appellate Body Report, US – Zeroing (Japan), para. 126.

101. As we understand it, the United States' position th at simple zeroing is permitted in periodic
reviews is premised on the argument that "dumping" and "dumping margins" can be found to exist at
the level of individual transactions and for individual importers when assessing the anti-dumping duty
liability for each importer. Under this argument, individual transactions where the export price
exceeds the normal value are "non-dumped" transacti ons and can be disregarded for the purpose of
determining importer-specific duty assessment rates. Furthermore, the United States argues that
Article 9.3 deals with only transaction-specific comparisons, and that it does not require the
aggregation of the results of such comparisons in order to determine a margin of dumping for the
relevant exporter.
218 The United States points out that, in the calculation of a duty assessment rate for
a particular importer, the value of all sales made to that importer is included in the denominator
merely for the sake of convenience to enable the customs authorities to apply a single duty assessment
rate to all such sales.219
102. Article 9.3.1 of the Anti-Dumping Agreement is subject to the overarching requirement in
Article 9.3 that the amount of anti-dumping duty "shall not exceed the margin of dumping as
established under Article 2" of that Agreement. We recall that our examination of the context of
Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement confirmed that the
term "margin of dumping", as used in those provisi ons, relates to the "exporter" of the "product"
under consideration and not to indivi dual "importers" or "import transactions", and, furthermore, that
the concepts of "dumping" and "dumping marg in" apply in the same manner throughout the Anti-
Dumping Agreement and do not vary under the various provisions of the Agreement.
220 Thus, under
Article VI:2 and Article 9.3, the margin of dum ping established for an exporter in accordance with
Article 2 operates as a ceiling for the total amount of anti-dumping duties that can be levied on the
entries of the subject merchandise from that exporter.
103. We see no basis in Article VI:2 of the GATT 1994 or in Articles 2 and 9.3 of the Anti-
Dumping Agreement for disregarding the results of comparisons where the export price exceeds the
normal value when calculating the margin of dumpi ng for an exporter. The Appellate Body has
previously noted that other provisions of the Anti-Dumping Agreement are explicit regarding the
permissibility of disregarding certain matters. For example, Article 9.4 of the Anti-Dumping
Agreement expressly directs investigating authorities to disregard "any zero and de minimis margins"

218See supra, para. 80.
219At the oral hearing, the United States argued that the definition of dumping applies at a transaction-
specific level in a periodic review, and that the margin of dumping therefore relates to an individual transaction.
Any transaction obviously is specific to both an exporter and an importer, and so, in that sense, dumping is
importer-specific and also exporter-specific. (United States' response to questioning at the oral hearing)
220See also Appellate Body Report, US – Zeroing (Japan), para. 114.

under certain circumstances, when calculating the weighted average margin of dumping to be applied
to exporters that have not been individually inves tigated. Similarly, Article 2.2.1, which deals with
the calculation of normal value, sets forth the only circumstances under which sales of the like
product in the exporting country can be disregarded. Thus, when the negotiators sought to permit
investigating authorities to disregard certain matters, they did so explicitly.221
104. We further recall that, based on its analysis of Article VI:1 of the GATT 1994 and Article 2.1
of the Anti-Dumping Agreement, the Appellate Body emphasized, in US – Softwood Lumber V, that:
[i]t is clear that an investigating authority may undertake multiple
averaging to establish margins of dumping for a product under
investigation. ... [T]he results of the multiple comparisons at the sub-
group level are, however, not "margins of dumping" within the
meaning of Article 2.4.2. Rather, those results reflect only
intermediate calculations made by an investigating authority in the
context of establishing margins of dumping for the product under
investigation. Thus, it is only on the basis of aggregating all these
"intermediate values" that an i nvestigating authority can establish
margins of dumping for the product under investigation as a whole.
222
(original emphasis)
105. In that appeal, the Appellate Body upheld the panel's finding that the use of zeroing under the
W-W comparison methodology in an original investig ation was inconsistent with Article 2.4.2 of the
Anti-Dumping Agreement.223 In US – Zeroing (EC) and in US – Zeroing (Japan), the Appellate Body
confirmed its interpretation of Article VI:1 and Ar ticle 2.1 and found that the use of zeroing was also
prohibited in the context of duty assessment proceedings under Article 9.3 of the Anti-Dumping
Agreement.224 The Appellate Body further emphasized that:
[i]f, as a consequence of zeroing, the results of certain comparisons
are disregarded only for purposes of calculating margins of dumping,
but taken into consideration for de termining injury, this would mean
that the same transactions are treated as "non-dumped" for one
purpose, and as "dumped" for another purpose. This is not in

221See Appellate Body Report, US – Softwood Lumber V, para. 100.
222Ibid., para. 97.
223Ibid., para. 117.
224See Appellate Body Report, US – Zeroing (EC) , paras. 125 and 135; and Appellate Body Report,
US – Zeroing (Japan) , paras. 166 and 176. The issue of zeroing also arose in US – Corrosion-Resistant Steel
Sunset Review, where the Appellate Body reversed the panel's finding that the use of zeroing in a sunset review
was not inconsistent with Articles 2.4 and 11.3 of the Anti-Dumping Agreement. The Appellate Body did not,
however, complete the analysis because of insufficient factual panel findings and facts undisputed by the parties.
(Appellate Body Report, US – Corrosion-Resistant Steel Sunset Review, paras. 133-138)

consonance with the need for consis tent treatment of a product in an
anti-dumping investigation.
225 (footnote omitted)
106. We also note that, while investigating author ities may define the scope of a product for an
anti-dumping investigation, that definition applies throughout the investigation. "Dumping", within
the meaning of the Anti-Dumping Agreement , can "be found to exist only for the product under
investigation as a whole" 226, by fully taking into account all the transactions pertaining to that
product.227 That definition of the product has implicati ons for subsequent stages of an anti-dumping
proceeding as well. In particular, we consider that the application of simple zeroing in periodic
reviews may result in certain models of the produ ct under investigation not being fully taken into
account at the duty assessment stage.
107. We fail to see a textual or contextual basis in the GATT 1994 or the Anti-Dumping Agreement
for treating transactions that occur above normal value as "dumped" for purposes of determining the
existence and magnitude of dumping in the origin al investigation and as "non-dumped" for purposes
of assessing the final liability for payment of an ti-dumping duties in a periodic review. Such
treatment brings about the following inconsistencies. First, as noted above, the transactions that are
disregarded may well pertain to a model, type, or class that fell within the definition of the product
under investigation and were treated as "dumped" in the original investigation. By excluding these
transactions at the duty assessment stage, a mismat ch is created between the product considered
"dumped" and the product as defined by the investigating authority.
108. Secondly, and more importantly, this treatment is inconsistent with the manner in which
injury was determined in the original investiga tion, where transactions that occurred at above the
normal value were taken into account in order to calculate the volume of dumped imports for
purposes of injury determination. 228 Obviously, we do not suggest th at there need be a fresh injury
determination at the duty assessment stage; rather, we wish to point to the contradiction that arises
when the same type of transactions are treated as "dumped" for purposes of injury determination in
the original investigation and as "non-dumped" in periodic reviews for duty assessment.
109. In addition, as we see it, a reading of Article 9.3 of the Anti-Dumping Agreement that
permits simple zeroing in periodic reviews would allow WTO Members to circumvent the prohibition
of zeroing in original investigations that applies under the first sentence of Article 2.4.2 of the Anti-

225Appellate Body Report, US – Zeroing (Japan), para. 128.
226Appellate Body Report, US – Softwood Lumber V, para. 93.
227Ibid. See also Appellate Body Report, US – Zeroing (Japan) , para. 115. See also Appellate Body
228See also supra, para. 73.

Dumping Agreement. This is because, in the first periodic re view after an original investigation, the
duty assessment rate for each importer will take effect from the date of the original imposition of anti-
dumping duties. Consequently, zeroing would be intr oduced although it is not permissible in original
investigations. We further note that, if no periodi c review is requested, the final anti-dumping duty
liability for all importers will be assessed at the cash deposit rate applicable to the relevant exporter.
When the initial cash deposit rate is calculated in th e original investigation without using zeroing, this
means that the mere act of conducting a periodic review would introduce zeroing following
imposition of the anti-dumping duty order.
110. We also wish to draw attention to certain other aspects of the United States' duty assessment
system, which are relevant for our analysis. First, if all sales made by an exporter to a particular
importer are found to have occurred at above normal va lue, the duty assessment rate applicable to that
importer will be zero for the period under review. However, the importer concerned will still be liable
to pay a cash deposit for its future imports at the ra te applicable to the relevant exporter if that
exporter has made sales at below norma l value to some other importers. 229 Secondly, in a periodic
review, a going-forward cash deposit rate is calculate d in respect of the relevant exporter, and all
importers importing from that exporter will pay cash de posits at that rate for future entries of the
subject merchandise, regardless of the importer-specific duty assessment rates calculated for each
importer for the previous period. These aspects indicate that the duty assessment and collection
system of the United States is not entirely impor ter-driven, but depends as well on exporter-related
determinations. The fact that the final liability of all importers would be assessed at the exporter's
cash deposit rate, if no periodic review is requested, also confirms this conclusion.
D. Periodic Reviews and Importer-specific Duty Assessment
111. The United States and the Panel have expressed cer tain concerns regarding the implications
for importer-specific duty assessment in periodic reviews that flow from the Appellate Body's
interpretation of Article 9.3 of the Anti-Dumping Agreement in previous disputes. The United States
argues that, if, under US – Zeroing (EC) and US – Zeroing (Japan) , "the amount of one importer's
antidumping margin must be averaged to account for the amount by which some other transaction
involving an entirely different importer was sold at above normal value, and vice versa , then an
importer could be subjected to liability for dumped imports made by another importer over whom [it]
has no control."
230 According to the United States, this w ould also mean that "the importer who is

229At the oral hearing, the United States explained that the rationale for this approach is that the
exporter's pricing behaviour is unpredictable.

engaged in dumped transactions would receive a windfall, because [it] may escape antidumping
duties, or have [its] liability sharply reduced th rough the actions of another importer who behaved
responsibly by eliminating its dumping margin."
231 In the same vein, the Panel expressed the concern
that "importers with high margins of dumping woul d be favoured at the expe nse of importers who do
not dump or who dump at a lower margin."232
112. It appears to us that the United States a nd the Panel have not correctly understood the
Appellate Body's interpretation of Article 9.3 in previous disputes. First, the Appellate Body has not
recognized the notion of "an importer's dumping margin" and has not held that "an importer's
dumping margin must be averaged out". 233 Rather, the Appellate Body has consistently held that
"margin of dumping" is an exporter-specific concep t, and that, whatever methodology is followed for
assessment and collection of anti-dumping duties, the total amount of anti-dumping duties assessed
and collected from all importers must not exceed th e total amount of dumping found in all the sales
made by the exporter concerned, calculated accordi ng to the margin of dumping established for that
exporter without zeroing.234 Secondly, the Appellate Body has also consistently held that "dumping"
and "margin of dumping" do not exist at the level of individual transactions, and that, therefore, the
terms "dumping" and "margin of dumping" cannot be interpreted as applying at an individual
transaction level, as the United States suggests. 235 Thirdly, with respect to assessment of anti-
dumping duty, however, the Appellate Body has recognized that, under Article 9.3, anti-dumping duty
liability can be assessed in relation to a specific im porter on the basis of its transactions from the
relevant exporter.
113. We do not agree that the Appellate Body's interpretation of Article 9.3 would favour
"importers with high margins of dumping … at th e expense of importers who do not dump or who
dump at a lower margin", as the Panel suggests. 236 In our view, it is not correct to say that, under the
Appellate Body's interpretation, an "offset" is pr ovided for the so-called "non-dumped" transactions.

232Panel Report, para. 7.146.
233The Appellate Body stated, in US – Zeroing (EC), that:
... a reading of Article 9.3 of the Anti-Dumping Agreement and Article VI:2
of the GATT 1994 does not suggest that final anti-dumping duty liability
cannot be assessed on a transaction- or importer -specific basis, or that the
investigating authorities may not use specific methodologies that reflect the
distinct nature and purpose of proceedin gs governed by these provisions, ...
provided that the total amount of an ti-dumping duties that are levied does
not exceed the exporters' or foreign producers' margins of dumping.
(Appellate Body Report, US – Zeroing (EC), para. 131 (original emphasis; footnote omitted))
234See Appellate Body Report, US – Zeroing (Japan), para. 156.
235See ibid., paras. 115 and 151; and Appellate Body Report, US – Zeroing (EC), paras. 126 and 128.
236Panel Report, para. 7.146. We reiterate our view that importers do not "dump" and do not have
"dumping margins".

A margin of dumping is properly calculated under the Anti-Dumping Agreement only if all
transactions are taken into account, including those where the export prices exceed the normal value.
Moreover, our interpretation does not preclude a WT O Member applying a retrospective system from
assessing an importer's final anti-dumping duty liability on the basis of its own transactions, subject,
however, to the legal requirement that the prescrib ed overall margin of dumping for the exporter is
respected.237
114. In sum, the Appellate Body has ruled on the amount of anti-dumping duty that can be levied
in accordance with Article 9.3 of the Anti-Dumping Agreement, and not on how this amount is to be
collected from the importers. In addition, the Appellate Body has recognized that WTO Members
have flexibility in choosing their duty assessment and collection system within the parameters
highlighted above.
E. The Panel's Arguments Relating to Alleged Administrative Burden
115. The Panel stated that a prohibition of zeroing in periodic reviews "would unnecessarily
expand the scope of periodic reviews because the exporters would have to submit information
pertaining to all of their export transactions rather than those pertaining to the importer requesting the
review."
238 According to the Panel, this would "als o cause administrative in convenience because the
investigating authorities would have to analyze all that information and be unable to complete the
review in a timely manner."239
116. It appears that the Panel has misunderstood a procedural aspect of the United States' duty
assessment system. As Mexico points out, the USDOC Regulations do not give the USDOC the
discretion to limit the scope of a periodic review to only exports pertaining to the importer requesting
the review.240 As we have explained earlier 241, a periodic review under the United States' system can
be requested by any interested party. Howeve r, once a periodic review is conducted, the USDOC
examines contemporaneous data pertaining to an exporter's sales to all of the importers of the subject
merchandise and determines simultaneously a going-fo rward cash deposit rate to be applied to all

237The Appellate Body has previously stated that, if aggregation of the results of multiple comparisons
yields a negative value for a particular importer, "this would not mean that the authorities would be required ...
to compensate an importer for the amount of that negative value (that is, when export prices exceed normal
value)." (Appellate Body Report, US – Zeroing (Japan) , footnote 363 to para. 155 (quoting Appellate Body
Report, US – Zeroing (EC) , footnote 234 to para. 131)) We further note, as stated in paragraph 110 of this
Report, that, in the case of such an exporter, under the United States' system, cash deposits will continue to be
collected at the going-forward cash deposit rate applicable to the exporter concerned.
238Panel Report, para. 7.146.
239Ibid.
240See Mexico's appellant's submission, para. 83 and footnotes 64 and 65 thereto.
241Supra, para. 74.

future entries of that product from that exporter and an individual duty assessment rate for each
importer in order to assess the final liability for payment of anti-dumping duties by that importer for
the period under review.
242 The Panel's concern over additional administrative burden or
inconvenience is therefore misplaced.
F. Arguments Relating to Prospective Normal Value Systems
117. We turn next to examine the Panel's analysis relating to "prospective normal value" systems
referred to in Article 9.4(ii) of the Anti-Dumping Agreement.243
118. The Panel stated that Article 9.4(ii) "cl early provides for a prospective normal value
system".244 The Panel observed that, "[i]n a prospective normal value system, the importer's liability
is determined through the comparison of the price pa id by the importer in a given transaction and the
prospective normal value." 245 According to the Panel, under su ch a system, "prices paid in other
export transactions have no bearing on this importer's liability." 246 The Panel added that, "[i]n other
words, the fact that other importers do not dump, or dump at a lower margin, does not affect the
liability of an importer who imports at dumped prices."247
119. For the Panel, it would have been "quite illogical" 248 if the drafters of the Anti-Dumping
Agreement allowed prospective normal value systems a nd yet envisaged that duties collected under
such a system would be subject to a duty assessme nt proceeding under Article 9.3 "in a manner that
would require the authorities to calculate a margin of dumping not on the basis of the data pertaining
to the importer seeking the initiation of the proceedi ng, but based on the aggregated data pertaining to
the exporter(s) from whom the importer imports." 249 According to the Pane l, "[t]he prospective

242See Mexico's appellant's submission, para. 83 (referring to Issues and Decision Memorandum for the
Final Results of Review in the 2001/2003 Administrative Review of Automative Replacement Glass ("ARG")
Windshield from the People's Republic of China, A-570-867, 69 FR 61790, 21 October 2004 (Exhibit
MEX-13.1 submitted by Mexico to the Panel), pp. 10-11: "The regulation limits an importer's ability to request
an administrative review to its own producers or exporters. The purpose of this limitation is to allow only those
companies with a stake in the outcome to request an administrative review of the producers relevant to them.
Once the [USDOC] decides to conduct its review, however, any such review covers that producer's or exporter's
sales to all importers").
243Article 9.4(ii) provides that an anti-dumping duty applied to imports from exporters not examined
individually and not included in the examination shall not exceed "where the liability for payment of anti-
dumping duties is calculated on the basis of a prospectiv e normal value, the differ ence between the weighted
average normal value of the selected exporters or producers and the export prices of exporters or producers not
individually examined".
244Panel Report, para. 7.131.
245Ibid.
246Ibid.
247Ibid.
248Ibid., para. 7.133.
249Ibid.

normal value system is based on the notio n of transaction-based duty collection." 250 For the Panel,
"[t]he Appellate Body's reasoning that duties collected under such a system are nevertheless subject to
duty assessment proceedings just like other duties assess ed on a prospective basis is, therefore, far
from being convincing."251
120. As Mexico, the European Communities, and Japan point out, the Panel has failed to
distinguish between duty "collection" at the time of importation, on the one hand, and determinations
of the final duty liability of an importer and the ma rgin of dumping for an exporter, on the other
hand.252 The anti-dumping duty collected from each importer at the time of importation, under a
prospective normal value system, does not represent the "margin of dumping" under Article 9.3,
which, as the Appellate Body has found, is the margin of dumping for an exporter for all of its sales of
the subject merchandise into the country concerned. As the Panel itself observed, under Article 9.3.2,
the amount of duties collected on a pr ospective basis also is subject to review. Under a prospective
normal value system, a review can be triggered as well if the prospective normal value has been
improperly determined and thereby the ceili ng prescribed under Article 9.3 is breached.
Article 9.4(ii) does not exempt prospective norma l value systems from the requirement set out in
Article 9.3.
121. The Panel stated that, if "liability for anti- dumping duties can be determined on a transaction-
specific basis in a prospective normal value system , there is no reason why the same cannot be the
case in the context of the retrospective duty assessment system under Article 9.3.2." 253 It is true that,
in a prospective normal value system, anti-dumping duties are "collected" on only the individual
export transactions where the prices are less than th e prospective normal value, regardless of whether
prices of other export transactions are above the pr ospective normal value. However, as we have
stated above, a review can be requested if th e prospective normal value has been improperly
determined so as to result in collection of anti-dumping duties in excess of the ceiling prescribed in
Article 9.3. As the Appellate Body has stated, the Anti-Dumping Agreement is neutral as to the
different systems for levy and collection of anti-dumping duties.254

250Panel Report, para. 7.133.
251Ibid.
 252See Mexico's appellant's submission, paras. 49-5 1; European Communities' third participant's
253Panel Report, para. 7.131.
254See Appellate Body Report, US – Zeroing (Japan), paras. 162 and 163.

G. The Panel's Contextual Arguments Relating to the Second Sentence of Article 2.4.2 of
the Anti-Dumping Agreement
122. The Panel relied on the second sentence of Article 2.4.2 as context to justify its decision not
to follow the legal interpretation of the Appellate Body in US – Zeroing (Japan) . The second
sentence of Article 2.4.2 reads:
A normal value established on a weighted average basis may be
compared to prices of individual export transactions if the authorities
find a pattern of export prices which differ significantly among
different purchasers, regions or time periods, and if an explanation is
provided as to why such differences cannot be taken into account
appropriately by the use of a wei ghted average-to-weighted average
or transaction-to-transaction comparison.
We recall that, under the first sentence of Article 2.4.2, an investigating authority is "normally"
required to use one of the two symmetrical compar ison methodologies provided for in that sentence.
The second sentence of Article 2.4.2 provides an asymmetrical comparison methodology to address a
so-called pattern of "targeted" dumping found among certain purchasers, in certain regions, or during
certain time periods.
123. The Panel stated that an interpretation that prohi bits zeroing in all contexts would be contrary
to the principle of effective treaty interpretation, because it would mean that the application of the
second sentence of Article 2.4.2 would always yield the same mathematical result as that obtained by
applying the W-W comparison methodology of the first sentence, thereby rendering the second
sentence of Article 2.4.2 inutile.
255
124. Mexico responds to the Panel's interpretation of the second sentence of Article 2.4.2 in two
ways. First, it points out that the asymmetrical comparison methodology in Article 2.4.2 (which is
meant to be used against "targeted dumping") was not an issue before the Panel and that, therefore,
the Appellate Body need not rule on whet her zeroing is permitted under that provision.
256 Secondly,
the "mathematical equivalence" argument works onl y under the assumption that the weighted average
normal value used in the weighted average-to -transaction ("W-T") comparison methodology is
identical to that used in the W-W comparison met hodology. According to Mexico, this is not the
case under the United States' system. Instead, th e USDOC's Regulations "call for the use of

255See Panel Report, para. 7.136. The United States generally supports the Panel's interpretation of
Article 2.4.2. (See United States' appellee's submission, paras. 87-93).
256See Mexico's appellant's submission, para. 65.

contemporaneous monthly normal values in 'targe ted dumping' [W-T] situations, while mandating
period-long normal value averages (normally one year) for [W-W] comparisons."257
125. The European Communities, Japan, and Th ailand generally agree with Mexico. 258 I n
addition, Japan and Thailand argue that the second sentence of Article 2.4.2 is not relevant to the issue
of whether simple zeroing is permitted in periodic reviews.
126. We note that the United States did not contest before the Panel Mexico's assertion that, if the
determination of weighted average normal values was based on different time periods , dumping
margin calculations under these two methodologies would yield different mathematical results.259 We
further note the Panel's statement that a methodology based on a comparison of "monthly normal
values with individual export transactions is the same methodology prescribed in US Regulations for
investigations where targeted dumping is identified and the third comparison methodology is used"
260,
and that the United States did not dispute this statement. 261 In our view, this suggests that the
"mathematical equivalence" argument works only un der a specific set of assumptions, and that there
is uncertainty as to how the W-T comparison methodology would be applied in practice.262
127. In any event, the Appellate Body has explai ned that, "[b]eing an exception, the comparison
methodology in the second sentence of Article 2.4. 2 (weighted average-to-transaction) alone cannot
determine the interpretation of the two me thodologies provided in the first sentence". 263 A s t h e
Appellate Body has also said, it could be argued, in reverse, that permitting zeroing under the first
sentence of Article 2.4.2 "would enable inves tigating authorities to capture pricing patterns
constituting 'targeted dumping', thus rendering the third methodology inutile."264 The Appellate Body
has also observed, in US – Zeroing (Japan) , that, "[i]n order to unmask targeted dumping, an
investigating authority may limit the application of the W-T comparison methodology to the prices of
export transactions falling within the relevant pattern."
265 The Appellate Body has so far not ruled on
the question of whether or not zeroing is permissible under the comparison methodology in the second

257Mexico's appellant's submission, para. 67 (" obligan a usar el valor normal promedio mensual más
contemporáneo en situaciones de 'dumping dirigido', y obligar usar valores normales de periodos completos
(normalmente un año) cuando se trata de comparaciones promedio-contra-promedio").
258See European Communities' third participant's submission, paras. 239 and 240; Japan's third
participant's submission, paras. 80-83; and Thailand's third participant's submission, paras. 32-35.
259Panel Report, para. 7.140. (emphasis added)
260Ibid., para. 7.142. (footnote omitted)
261See ibid. and footnote 105 thereto (referring to United States' response to Question 5 posed by the
Panel at the second panel meeting).
262See also Appellate Body Report, US – Softwood Lumber V (Article 21.5 – Canada), para. 99.
263Ibid., para. 97.
264Appellate Body Report, US – Zeroing (Japan) , para. 133 (quoting Appellate Body Report, US –
Softwood Lumber V (Article 21.5 – Canada), para. 100 (original emphasis)).
265Ibid., para. 135.

sentence of Article 2.4.2. Nor is it an is sue before us in this appeal. As in US – Zeroing (Japan), our
analysis here of the second sentence of Article 2.4.2 is therefore confined to addressing the contextual
arguments of the Panel based on that provision.
266
H. Historical Background
128. We do not consider it strictly necessary in this case to have recourse to the supplementary
means of interpretation identified in Article 32 of the Vienna Convention because our analysis under
Article 31 has not left the meaning of the relevant provisions of the Anti-Dumping Agreement
"ambiguous or obscure", nor has it led to a "manifest ly absurd or unreasonable" result. Nevertheless,
we turn to examine the United States' arguments relating to the historical background of the Anti-
Dumping Agreement.
129. The United States argues that recourse to th e circumstances of the conclusion of the Anti-
Dumping Agreement is appropriate in this case as a s upplementary means of interpretation under
Article 32 of the Vienna Convention . The United States refers to various historical materials,
including the 1960 Group of Experts Report, two pre-WTO panel reports267 that dealt with the issue of
zeroing in the context of the Tokyo Round Anti-Dumping Code , and several proposals submitted
during the Uruguay Round. 268 According to the United States, the historical materials demonstrate
that the negotiators were not able to agree on a ge neral prohibition of zeroing or on a requirement to
aggregate individual transactions under Article 9.3 of the Anti-Dumping Agreement.269 The United
States submits that, throughout the history of the GATT, it was recognized that zeroing was allowed
under Article VI of the GATT 1947, and adds that this Article was not modified during the Uruguay
Round.270 According to the United States, "[n]o c onsensus could be reach ed because despite
extensive efforts by Japan, Hong Kong, Singapore, and the Nordic Countries, their proposals [for
prohibiting zeroing] were firmly opposed by the [European Communities], the United States and
Canada." 271

266See Appellate Body Report, US – Zeroing (Japan) , para. 136. Accordingly, the inferences that the
Panel seeks to draw as to the Appellate Body's inte rpretation of the second sentence of Article 2.4.2 are
misguided. (See Panel Report, paras. 7.138 and 7.139)
267Panel Report, EC – Audio Cassettes , circulated 28 April 1995, unadopted; Panel Report, EEC –
Cotton Yarn, adopted 30 October 1995.
268See United States' appellee's submission, paras. 59-64.
269See ibid., paras. 114, 126, and 128.
270See ibid., paras. 126 and 127.
271Ibid., para. 128 (referring to Communications from Japan, MTN.GNG/NG8/W/11 and
MTN.GNG/NG8/W/30; Proposals by Hong Kong, China, MTN.GNG/NG8/W/51/Add.1 and
MTN.GNG/NG8/W/46; Proposal by Singapore, MTN.GNG/NG8/W/55; and Proposal by the Nordic
Countries, MTN.GNG/NG8/W/76). See also ibid., paras. 114-128.

130. We are not persuaded that the aforementioned historical materials provide guidance as to
whether simple zeroing is permissible under Article 9.3 of the Anti-Dumping Agreement. First, as we
see it, the negotiating proposals referred to by the United States reflect the positions of only some of
the negotiating parties. Japan argued at the oral hearing that, contrary to what the United States
suggests, if certain proposals on zeroing were not expressly included in the text, it is because the
negotiators considered that the new Uruguay Round Anti-Dumping Agreement prohibited zeroing.
The European Communities, in turn, suggests that there is a "strong indication of consensus that the
interests of both parties in the asymmetry and zeroi ng debate could be accomm odated in the targeted
dumping provisions that eventually became the second sentence of Article 2.4.2".
272
131. Secondly, we note that the same historical materials referenced by the United States were
examined by the Appellate Body in US – Softwood Lumber V 273, where the Appellate Body
concluded that these materials did not resolve the issue of whether the negotiators of the Anti-
Dumping Agreement intended to prohibit zeroing. Alt hough the 1960 Group of Experts Report
concluded that making an injurious dumping determ ination based on individual transactions was the
"ideal method", it also regarded su ch method as "clearly impracticable". 274 This report is of little
relevance to our analysis and does not shed light on the determination of a margin of dumping under
Article 9.3 of the Anti-Dumping Agreement. In addition, even if we were to assume that zeroing was
permitted under Article VI of the GATT 1947, Article VI of the GAT T 1994 has to be interpreted
now in conjunction with the relevant provisions of the Anti-Dumping Agreement, such as Articles 2.1,
2.4, 2.4.2, and 9.3.
132. Thirdly, the Anti-Dumping Agreement entered into force in 1995, as part of the results of the
Uruguay Round negotiations, long after the 1960 Group of Experts Report. The Panel Reports in
EC – Audio Cassettes (unadopted) and EEC – Cotton Yarn (adopted), referred to by the United States,
examined the issue of zeroing under the provisions of the Tokyo Round Anti-Dumping Code . The
relevance of these panel reports is diminished by the fact that the plurilateral Tokyo Round Anti-
Dumping Code was legally separate from the GATT 1947 and h as, in any event, been terminated.
This Code was not incorporated into the WTO c overed agreements and, fu rthermore, it contained
provisions that were less detailed than those in the Anti-Dumping Agreement. In its arguments on the
permissibility of zeroing, the United States relies specifically on Article 2.6 of the Tokyo Round Anti-

272European Communities' third participant's submission, para. 226. (emphasis omitted) In response to
questioning at the oral hearing, the European Communities argued that the negotiating history of the second
sentence of Article 2.4.2 suggests further that investigating authorities are permitted to select low-priced export
transactions, in order to calculate a margin of dumping, only where a pattern of export prices for different
purchasers, regions, or time periods exists.
273See Appellate Body Report, US – Softwood Lumber V, para. 108.
274Supra, footnote 58, para. 8.

Dumping Code. We note that the corresponding provision in the Anti-Dumping Agreement, namely,
Article 2.4, has a different wording in that it contains a new first sentence. Moreover, the Tokyo
Round Anti-Dumping Code contained no provision similar to Article 2.4.2 of the Anti-Dumping
Agreement. Therefore, whatever the legal status of zeroing under the Tokyo Round Anti-Dumping
Code, it is of little relevance for the interpretation of differently phrased or new provisions of the Anti-
Dumping Agreement.
I. Conclusion
133. As noted above, when applying "simple zeroing" in periodic reviews, the USDOC compares
the prices of individual export transactions against monthly weighted average normal values, and
disregards the amounts by which the export prices exceed the monthly weighted average normal
values, when aggregating the results of the comp arisons to calculate the going-forward cash deposit
rate for the exporter and the duty assessment rate fo r the importer concerned. Simple zeroing thus
results in the levy of an amount of anti-dumping duty that exceeds an exporter's margin of dumping,
which, as we have explained a bove, operates as the ceiling for th e amount of anti-dumping duty that
can be levied in respect of the sales made by an exporter. Therefore, simple zeroing is, as such,
inconsistent with Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement.
134. For these reasons, we reverse the Panel's finding, in paragraphs 7.143 and 8.1(c) of the Panel
Report, that simple zeroing in periodic reviews is not, as such, inconsistent with Article VI:2 of the
GATT 1994 and Article 9.3 of the Anti-Dumping Agreement, and find, instead, that simple zeroing in
periodic reviews is, as such, inconsistent with th e United States' obligations under those provisions.
As a consequence, we also reverse the Panel's findings, in paragra phs 7.143 and 8.1(c) of the Panel
Report, that simple zeroing in periodic reviews is no t, as such, inconsistent with Article VI:1 of the
GATT 1994 and Article 2.1 of the Anti-Dumping Agreement . The Panel offers no additional
reasoning that could independently support its findings under those provisions.
135. We note that Mexico requests the Appellate Body not only to reverse the Panel's findings of
consistency, but also to find that simple zeroing in periodic reviews is, as such, inconsistent with the
United States' obligations under Article VI:1 of the GATT 1994 and Article 2.1 of the Anti-Dumping
Agreement.
275 As we have found that simple zeroing in pe riodic reviews is, as such, inconsistent with
Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement, we do not consider it

275Mexico confirmed at the oral hearing that, in making its claim under Article VI:1 of the GATT 1994,
it does not rely on the last sentence of that Article dealing with price comparability.

necessary to make an additional finding on Mexico 's claim under Article VI:1 of the GATT 1994 and
Article 2.1 of the Anti-Dumping Agreement.276
136. In our analysis, we have been mindful of the standard of review provided in Article 17.6(ii) of
the Anti-Dumping Agreement . However, we consider that Article VI:2 of the GATT 1994 and
Article 9.3 of the Anti-Dumping Agreement, when interpreted in accordan ce with the customary rules
of interpretation of public international law as require d by the first sentence of Article 17.6(ii) of the
Anti-Dumping Agreement, do not admit of another interpretation as far as the issue of zeroing raised
in this appeal is concerned.
VI. Simple Zeroing As Applied in Periodic Reviews
137. The Panel found that zeroing, as applied by the USDOC in the five periodic reviews at issue
in this dispute, is not inconsistent with Artic les VI:1 and VI:2 of the GATT 1994 and Articles 2.1
and 9.3 of the Anti-Dumping Agreement .277 In support of its findings, the Panel referred to the
reasoning that led it to conclude that simple zeroing in periodic reviews is not inconsistent with those
provisions.278
138. On appeal, Mexico requests the Appellate Body to reverse the Panel's findings under
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement
and to find, instead, that the United States acted inconsistently with its obligations under these
provisions.
139. We have found 279 that simple zeroing in periodic reviews is, as such, inconsistent with
Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement .280 F o r t h e s a m e
reasons, we reverse the Panel's finding, in paragraphs 7.149 and 8.1(d) of the Panel Report, that
zeroing, as applied by the USDOC in the five peri odic reviews at issue in this dispute, is not
inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-
Dumping Agreement, and find, instead, that the United States acted inconsistently with its obligations
under Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement in the five
periodic reviews at issue in this dispute.

276See also Appellate Body Report, US – Zeroing (Japan), para. 140.
277Panel Report, paras. 7.149 and 8.1(d).
278Ibid., para. 7.149.
279See supra, para. 134.
280See also Appellate Body Report, US – Zeroing (EC) , para. 133; and Appellate Body Report, US –
Zeroing (Japan), paras. 174-176.

140. In relation to Article VI:1 of the GATT 1994 and Article 2.1 of the Anti-Dumping Agreement,
we note that Mexico requests the Appellate Body no t only to reverse the Panel's findings, but also to
find that the United States acted inconsistently with these provisions.
281 However, having found that
zeroing, as applied by the USDOC in the five periodic re views at issue in this dispute, is inconsistent
with Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping Agreement , we do not
consider it necessary to make an additional findin g on Mexico's claim under Article VI:1 of the
GATT 1994 and Article 2.1 of the Anti-Dumping Agreement.282
VII. Article 2.4 of the Anti-Dumping Agreement
141. Before the Panel, Mexico argued that simple zer oing in periodic reviews is inconsistent with
Article 2.4 of the Anti-Dumping Agreement , because "a comparison that fails to take into account
certain export transactions cannot result in a determination of dumping for the product under
consideration as a whole and cannot be considered as a 'fair comparison' within the meaning of
Article 2.4."283 The Panel viewed Mexico's claim as being "premised on the assumption that
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement
prohibit simple zeroing in periodic reviews." 284 Having disagreed with Mexico's assertion that these
provisions "require investigating authorities in a periodic review to base their dumping determinations
on an aggregation of all export transactions from ea ch exporter", the Panel found that simple zeroing
in periodic reviews is not, as such, inconsistent with the obligation to make a "fair comparison"
between the normal value and the export price as stipulated in Article 2.4 of the Anti-Dumping
Agreement.285 The Panel further found that the United States did not, therefore, act inconsistently
with Article 2.4 in the five periodic reviews at issue in this dispute.
142. Mexico challenges the Panel's findings on appeal . Mexico argues that the Panel erred in
rejecting Mexico's arguments concerning the consis tency of simple zeroing in periodic reviews with
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement.286
In addition, Mexico argues that the Panel failed to conduct an "objective assessment of the matter", as
required under Article 11 of the DSU, by faili ng to address other "independent arguments" put
forward by Mexico that simple zeroing in periodic re views is inconsistent with the "fair comparison"
requirement in Article 2.4 because it "distorts the prices of certain export transactions by artificially

281See Mexico's appellant's submission, para. 101.
282See, supra, para. 133.
283Panel Report, para. 7.144.
284Ibid., para. 7.145.

reducing them, [thus] inflating the apparent magnitude of dumping" and because "calculating margins
of dumping [through the use of zeroing] is not impartial, even-handed, or unbiased."287
143. The Panel's finding that simple zeroing in periodi c reviews is not inconsistent with Article 2.4
of the Anti-Dumping Agreement is based on the Panel's reasoning and findings relating to
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-Dumping Agreement,
which we have reversed. The Panel offers no a dditional reasoning that c ould independently support
its finding under Article 2.4. As a consequence, we reverse the Panel's findings, in paragraphs 7.145
and 8.1(c) of the Panel Report, that simple zeroi ng in periodic reviews is not, as such, inconsistent
with Article 2.4 of the Anti-Dumping Agreement . We also reverse the Panel's findings, in
paragraphs 7.149 and 8.1(d) of the Panel Report, that the United States did not act inconsistently with
Article 2.4 in the five periodic reviews at issue in this dispute.
144. We note that Mexico requests the Appellate B ody not only to reverse the Panel's finding of
consistency, but also to find that simple zeroing in periodic reviews is inconsistent with the United
States' obligations under Article 2.4. As we ha ve found that simple zeroing in periodic reviews is,
as such, inconsistent with Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-Dumping
Agreement, we find it unnecessary to make an additional finding in relation to Mexico's "as such" and
"as applied" claims under Article 2.4. 288 For the same reason, we find it unnecessary to make an
additional finding on Mexico's claim that the Panel acted inconsistently with Article 11 of the DSU by
failing to address certain "independent" arguments put forward by Mexico in support of its claim
under Article 2.4.

287Mexico's appellant's submission, para. 92 ("argumentos independientes"; "distorsiona los precios de
ciertas transacciones al reducir de manera artificial e inflar … la magnitud del dumping "; " cálculo de los
márgenes de dumping [por la utilización de la reducción a cero] no es imparcial, equitativa ni justa").
288We recall that, in US – Zeroing (EC) , the Appellate Body considered that, in the light of its earlier
finding that zeroing as applied in the periodic review s at issue was inconsistent with Article 9.3 of the Anti-
Dumping Agreement and Article VI:2 of the GATT 1994, additional findings under Article 2.4 of the Anti-
Dumping Agreement were not necessary to resolve that dispute. (Appellate Body Report, US – Zeroing (EC) ,
para. 147) In that same appeal, the Appellate Body wa s unable to complete the an alysis and determine whether
zeroing in periodic reviews was, as such, inconsistent with the "fair comparison" requirement in Article 2.4.
(Ibid., para. 228) In US – Softwood Lumber V (Article 21.5 – Canada), the Appellate Body found that the use of
zeroing in calculating the margins of dumping unde r the T-T comparison methodology in the original
investigation at issue in that dispute was inconsistent with the "fair comparison" requirement in Article 2.4 of
the Anti-Dumping Agreement . (Appellate Body Report, US – Softwood Lumber V (Article 21.5 – Canada) ,
para. 146) In US – Zeroing (Japan) , the Appellate Body found that zeroing in periodic reviews is, as such,
inconsistent with Article 2.4 of the Anti-Dumping Agreement. (Appellate Body Report, US – Zeroing (Japan) ,
para. 169)

VIII. Mexico's Claim under Article 11 of the DSU Concerning the Panel's Failure to Follow
Previous Adopted Appellate Body Reports Addressing the Same Issues
145. We turn next to address Mexico's claim that th e Panel acted inconsistently with Article 11 of
the DSU because, by making findings and conclusions that are identical to those that have been
reversed by the Appellate Body in previous disp utes, it failed to assist the DSB in discharging its
responsibilities under the DSU and the covered agreements.
A. The Panel's Findings and Mexico's Appeal
146. At the outset of its analysis, the Panel r ecalled previous Appella te Body jurisprudence
regarding the relevance of adopted panel and Appellate Body report s for future panels addressing the
same issues. The Panel referred to the Appellate Body Report in Japan – Alcoholic Beverages II ,
where the Appellate Body said that, although adopte d panel reports are not binding, except with
respect to resolving the particular dispute between the parties, they should be taken into account
where they are relevant to any dispute.
289 The Panel also referred to the Appellate Body's statement in
US – Oil Country Tubular Goods Sunset Reviews, that "following the Appellate Body's conclusions in
earlier disputes is not only appropriate, [it] is what would be expected from panels, especially where
the issues are the same." 290 Nevertheless, the Panel decided not to follow the legal interpretation of
the Appellate Body in US – Zeroing (EC) and US – Zeroing (Japan) , where the Appellate Body
found that simple zeroing in periodic reviews is in consistent with Article VI:2 of the GATT 1994 and
Article 9.3 of the Anti-Dumping Agreement.291 Instead, the Panel relied on findings in panel reports
that the Appellate Body has reversed.
147. On appeal, Mexico argues that the Panel's approach was inconsistent with the first sentence of
Article 11 of the DSU, which stipulates that the func tion of panels is to assist the DSB in discharging
its responsibilities under the DSU. In support of its clai m, Mexico refers to Articles 3.2 and 3.3 of the
DSU, which state that the dispute settlement system is a "central element in providing security and
predictability to the multilateral trading system" an d that the "prompt settlement of situations" is
"essential to the effective functioning of the WT O". Mexico emphasizes that the Panel acted
inconsistently with Article 11 of the DSU by faili ng "to follow a consistent line of adopted Appellate
Body reports that address identical issues with respect to the same responding party" 292 and, as a

289Panel Report, para. 7.103 (referring to Appellate Body Report, Japan – Alcoholic Beverages II ,
p. 14, DSR 1996:I, 97, at 108.
290Ibid., para. 7.104 (quoting Appellate Body Report, US – Oil Country Tubular Goods Sunset Reviews,
para. 188).
291See ibid., para. 7.106.

result, by making findings that are identical to those that have been expressly reversed by the
Appellate Body in previous cases. Mexico maintain s that it was compelled to appeal because of the
Panel's departure from previous Appellate Body reports. In Mexico's view, this "interfere[d] with the
prompt settlement of this dispute and, thereby, frustrate[d] the effective functioning of the WTO
dispute settlement system".293
148. The United States requests the Appellate Body to reject Mexico's claim. According to the
United States, the Panel made an objective assess ment of the matter by "conduct[ing] its own,
objective review of the applicable facts and la w to come up with findings to assist the DSB." 294 The
United States further submits that the Panel "caref ully considered and took into account the Appellate
Body's previous rulings on zeroing and explained in detail why it did not believe they should apply in
this case."295 With respect to the "expectation" that panels follow adopted panel and Appellate Body
reports, the United States disagrees with Mexico that a failure to meet this expectation could
constitute a violation of Article 11 of the DSU. The United States also refers to the last sentence of
Article 3.2 of the DSU, which states that recommend ations and rulings of the DSB cannot add to or
diminish the rights and obligations provided in the covered agreements.
149. The European Communities, Japan, and Thailand support Mexico's claim that the Panel acted
inconsistently with its obligati ons under Article 11 of the DSU. 296 The European Communities
submits that the legal questions that the Panel had to deal with are the same as those that were before
the Appellate Body in previous cases. The Eur opean Communities underlines that the Panel did not
"distinguish"297 the legal issues raised by Mexico in the present case from those addressed by the
Appellate Body in previous cases. Although th e European Communities ac knowledges that case law
can change if there are cogent reasons for such a change298, such a change could not be justified solely
on the basis of a disagreement by the hierarch ically lower body with the reasoning of the
hierarchically higher body in the WTO dispute settlement system. 299 The European Communities
therefore requests the Appellate Body to make it unambiguous that panels are not only expected, but
also obliged, to follow Appellate Body findings.

295Ibid., para. 131.
296See European Communities' third participant's subm ission, para. 35; Japan's third participant's
submission, para. 13; and Thailand's third participant's submission, paras. 14 and 15.
297European Communities' third participant's submission, para. 53.
298See ibid., para. 50; and European Communities' first written submission to the Panel,
paras. 141-144.
299See European Communities' third participant's submission, para. 51.

150. Japan contends that, where a subsequent di spute involves the same matter as an adopted
report, the adopted report "clarifies" the respondent's obligations with respect to the specific matter
and creates expectations among other WTO Members of their rights with respect to that matter.
300
Japan adds that "a panel that sets aside adopted rulings on the same 'matter'" 301 acts inconsistently
with its obligations under Article 11 of the DSU, because it substitutes its own "subjective assessment
of the matter for one that carries the approval of the DSB".302
151. Thailand maintains that, for a multi-tiered system of adjudication to function effectively and
to provide "security and predictability", the hierar chy between the two tiers in the system must be
respected. Thailand further maintains that, if WTO Members cannot be confident that the decisions of
panels will be consistent with the jurisprudence of the Appellate Body, they will lose confidence in
the WTO dispute settlement process; they will see WTO dispute settlement proceedings as requiring
an appeal in every dispute in order to obtain an objective assessment of the matter. 303 According to
Thailand, this would increase the cost of using the system, diminish efficiency, and be particularly
harmful for developing countries.304
152. According to Chile, the Panel's findi ngs may create a "vicious circle" 305 that would not
provide security and predictability to the dispute settlement system. Nonetheless, Chile argues that,
while panels are expected to follow Appellate Body jurisprudence, they are under no obligation to do
so. Therefore, the fact that a panel did not do what was expected of it cannot, in and of itself,
constitute a violation of Article 11 of the DSU.
306
153. Having recalled the participants' arguments on appeal, we turn to an examination of Article 11
of the DSU.

300See Japan's third participant's submission, paras. 15 and 19.
301Ibid., para. 18.
302Ibid.
303See Thailand's third participant's submission, para. 14.
304See ibid., para. 15.
305Chile's third participant's submission, p. 1 ("círculo vicioso").
306See ibid., p. 2.

B. Analysis
154. On appeal, Mexico argues that the Panel acted in consistently with Article 11 of the DSU by
failing to follow well-established A ppellate Body jurisprudence. In support of its claim, Mexico
refers to Articles 3.2 and 3.3 of the DSU.
155. We begin our consideration with the text of Article 11 of the DSU, which sets forth the
function of panels in the WTO dispute settlement sy stem. The first sentence stipulates that "[t]he
function of panels is to assist the DSB in disch arging its responsibilities" under the DSU and the
covered agreements. The second sentence states that "a panel should make an objective assessment of
the matter before it, including an objective assessment of the facts of the case and the applicability of
and conformity with the relevant covered agreements, and make such other findings as will assist the
DSB in making the recommendations or in giving the rulings provided for in the covered
agreements."
156. Mexico stated at the oral hearing that its cl aim focuses on the first sentence of Article 11 of
the DSU
 . However, we observe that the second sen tence of Article 11 begins with the term
"Accordingly". This term creates a link between the first and the second sentence of Article 11 307; it
ties the second sentence to the general description contained in the first sentence. The second
sentence enunciates two specific "functions" of pa nels, namely, the duty "to make an objective
assessment of the matter before it" and "to make su ch other findings as will assist the DSB in making
the recommendations or in giving the rulings" under the covered agreements.
157. We consider the meaning of "[t]he function of panels" in the first sentence of Article 11 is
informed by the general provisions contained in Article 3 of the DSU, which sets out the basic
principles of the WTO dispute settlement system. Ar ticle 3.2 provides that "[t]he dispute settlement
system of the WTO is a central element in provi ding security and predicta bility to the multilateral
trading system"; it serves "to preserve the right s and obligations of Members under the covered
agreements, and to clarify the existing provisions of those agreements in accordance with customary
rules of interpretation of public international law."

307The word "accordingly" is used in a similar way in Article 2 of the DSU. There, the first sentence
establishes the DSB. In the second sentence, starting wi th the word "accordingly", the DSB is provided with
"the authority to establish panels, adopt panel and Appellate Body reports, maintain surveillance of
implementation of rulings and recommendations, and authorize suspension of concessions and other obligations
under the covered agreements."

158. It is well settled that Appellate Body reports are not binding, except with respect to resolving
the particular dispute between the parties.
308 This, however, does not mean that subsequent panels are
free to disregard the legal interpretations and the ratio decidendi contained in previous Appellate
Body reports that have been adopted by the DSB. 309 In Japan – Alcoholic Beverages II, the Appellate
Body found that:
[a]dopted panel reports are an important part of the GATT acquis.
They are often considered by s ubsequent panels. They create
legitimate expectations among WT O Members, and, therefore,
should be taken into account where they are relevant to any
dispute.
310
159. In US – Shrimp (Article 21.5 – Malaysia) , the Appellate Body clarified that this reasoning
applies to adopted Appellate Body reports as well. 311 I n US – Oil Country Tubular Goods Sunset
Reviews, the Appellate Body held that "following the A ppellate Body's conclusions in earlier disputes
is not only appropriate, but is what would be expected from panels, especially where the issues are the
same."312
160. Dispute settlement practice demonstrates that WTO Members attach significance to reasoning
provided in previous panel and A ppellate Body reports. Adopted pa nel and Appellate Body reports
are often cited by parties in support of legal ar guments in dispute settlement proceedings, and are
relied upon by panels and the Appellate Body in sub sequent disputes. In addition, when enacting or
modifying laws and national regulations pertaining to international trade matters, WTO Members take
into account the legal interpretation of the cove red agreements develope d in adopted panel and
Appellate Body reports. Thus, the legal interpretation embodied in adopted panel and Appellate Body

308See Appellate Body Report, Japan – Alcoholic Beverages II, pp. 12-15, DSR 1996:I, 97, at 106-108.
In that case, the Appellate Body stated:
It is worth noting that the Statute of the International Court of Justice has an
explicit provision, Article 59, to the same effect. This has not inhibited the
development by that Court (and its predecessor) of a body of case law in
which considerable reliance on the value of previous decisions is readily
discernible.
(Ibid., p. 14, footnote 30, DSR 1996:I, 97, at 108) See also Appellate Body Report, US – Softwood Lumber V ,
paras. 109-112; Appellate Body Report, US – Shrimp (Article 21.5 – Malaysia), para. 109.
While Appellate Body reports adopted by the DSB shall be accepted unconditionally by the parties to
the dispute, it is the exclusive authority of the Ministerial Conference and the General Council to adopt,
pursuant to Article IX:2 of the WTO Agreement, interpretations that are binding upon the WTO membership.
309We note that the mandate of an Article 21.5 panel includes the task of assessing whether the
measures taken to comply with the rulings and r ecommendations adopted by the DSB in the original
proceedings achieve compliance with those rulings. Therefore, panels established under that provision are
bound to follow the legal interpretation contained in the original panel and Appellate Body reports that were
adopted by the DSB.
310Appellate Body Report, Japan – Alcoholic Beverages II, p. 14, DSR 1996:I, 97, at 108.
311See Appellate Body Report, US – Shrimp (Article 21.5 – Malaysia), para. 109.
312Appellate Body Report, US – Oil Country Tubular Goods Sunset Reviews, para. 188.

reports becomes part and parcel of the acquis of the WTO dispute settlement system. Ensuring
"security and predictability" in the dispute settlement system, as contemplated in Article 3.2 of the
DSU, implies that, absent cogent reasons, an adjudicatory body will resolve the same legal question in
the same way in a subsequent case.313
161. In the hierarchical structure contemplated in the DSU, panels and the Appellate Body have
distinct roles to play. In order to strengthen di spute settlement in the multilateral trading system, the
Uruguay Round established the Appellate Body as a st anding body. Pursuant to Article 17.6 of the
DSU, the Appellate Body is vested with the author ity to review "issues of law covered in the panel
report and legal interpretations deve loped by the panel". Accordingly, Article 17.13 provides that the
Appellate Body may "uphold, modify or reverse" the legal findings and conc lusions of panels. The
creation of the Appellate Body by WTO Members to review legal interpretations developed by panels
shows that Members recognized the importance of c onsistency and stability in the interpretation of
their rights and obligations under the covered agreem ents. This is essential to promote "security and
predictability" in the dispute settlement system, an d to ensure the "prompt settlement" of disputes.
The Panel's failure to follow previously adopted Appellate Body reports addressing the same issues
undermines the development of a coherent and predic table body of jurisprudence clarifying Members'
rights and obligations under the covered agreements as contemplated under the DSU. Clarification, as
envisaged in Article 3.2 of the DSU, elucidates the scope and meaning of the provisions of the
covered agreements in accordance with customary rul es of interpretation of public international law.
While the application of a provision may be regard ed as confined to the context in which it takes
place, the relevance of clarification contained in a dopted Appellate Body reports is not limited to the
application of a particular provision in a specific case.

313See H. Lauterpacht, "The so-called Anglo-American and Continental Schools of Thought in
International Law" (1931) 12 British Yearbook of International Law 53, who points out that adherence to legal
decisions "is imperative if the law is to fulfil one of its primary functions, i.e. the maintenance of security and
stability". Consistency of jurisprudence is valued also in dispute settlement in other international fora.
In this respect we note the Decision of the Interna tional Criminal Tribunal for the Former Yugoslavia,
Case No. IT-95-14/1-A, Prosecutor v. Aleksovski, Judgement of 24 March 2000, para. 113, which states that
"the right of appeal is ... a component of the fair trial requirement, which is itself a rule of customary
international law and gives rise to the right of the accuse d to have like cases treated alike. This will not be
achieved if each Trial Chamber is free to disregard decisions of law made by the Appeals Chamber, and decide
the law as it sees fit." Furthermore, we note the Decision of 21 March 2007 of the ICSID (International Centre
for Settlement of Investment Disputes) Arbitration Tribunal, Case No. ARB/05/07, Saipem S.p.A. v. The
People's Republic of Bangladesh , ICSID IIC 280 (2007), p. 20, para. 67, which states that "[t]he Tribunal
considers that it is not bound by previous decisions. At the same time, it is of the opinion that it must pay due
consideration to earlier decisions of international tribuna ls. It believes that, subject to compelling contrary
grounds, it has a duty to adopt solutions established in a series of consistent cases. It also believes that, subject
to the specifics of a given treaty and of the circumstances of the actual case, it has a duty to seek to contribute to
the harmonious development of investment law and thereby to meet the legitimate expectations of the
community of States and investors towards certainty of the rule of law."

162. We are deeply concerned about the Panel's d ecision to depart from well-established Appellate
Body jurisprudence clarifying the interpretation of the same legal issues. The Panel's approach has
serious implications for the proper functioning of the WTO dispute settlement system, as explained
above. Nevertheless, we consider that the Pane l's failure flowed, in essence, from its misguided
understanding of the legal provisions at issue. Si nce we have corrected the Panel's erroneous legal
interpretation and have reversed all of the Panel's findings and conclusions that have been appealed,
we do not, in this case, make an additional finding that the Panel al so failed to discharge its duties
under Article 11 of the DSU.
IX. Time-limits for Filing Submissions
163. In a letter dated 3 March 2008, the European Communities complained that the United States'
appellee's submission was submitted almost three hour s after the time-limit set out by the Appellate
Body in the Working Schedule for this appeal, communicated to the participants and third participants
on 1 February 2008. The European Communities subm its that the United States "had significant time
to examine the filings of the Third Participants and eventually adjust its own submission prior to
filing."
314 At the oral hearing, the European Commun ities reiterated its request that the Appellate
Body clarify whether it considers the United Stat es' appellee's submission to be filed within the
meaning of Rule 18(1) of the Working Procedures, and what the consequences are, if any, of a late
filing.
164. We share the concerns raised by the Europ ean Communities. Compliance with established
time periods by all participants regarding the fili ng of submissions is an important element of due
process of law. The Appellate Body clarified in India – Patents (US) that due process requirements
are implicit in the DSU. 315 This is particularly important, gi ven that, according to Rules 22(1)
and 24(1) of the Working Procedures , the appellee's submission(s) and the third participant's
submission(s) are filed contemporaneously. The late filing of a participant's submission could have
implications for the other participants. Complian ce with the procedural requirements relating to the
timely filing of submissions is a matter of fairness and orderly procedure, which are referred to in
Rule 16(1) of the Working Procedures. In the circumstances of this appeal, we nevertheless consider
the United States' appellee's submission as filed.

314Letter from the European Communities to the Appellate Body Secretariat, dated 3 March 2008, p. 2.
(emphasis omitted)
315See Appellate Body Report, India – Patents (US), para. 94.

X. Findings and Conclusions
165. For the reasons set out in this Report, the Appellate Body:
(a) reverses the Panel's finding, in paragraphs 7. 143, 7.145, and 8.1(c) of the Panel
Report, that simple zeroing in periodic re views is not, as such, inconsistent with
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-
Dumping Agreement; and finds , instead, that simple zeroing in periodic reviews is,
as such, inconsistent with Article VI:2 of the GATT 1994 and Article 9.3 of the Anti-
Dumping Agreement;
(b) reverses the Panel's finding, in paragraphs 7.1 49 and 8.1(d) of the Panel Report, that
the United States did not act inconsistently with Articles VI:1 and VI:2 of the
GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping Agreement ; and
finds
, instead, that the United States acted inc onsistently with Article VI:2 of the
GATT 1994 and Article 9.3 of the Anti-Dumping Agreement by applying simple
zeroing in the five periodic reviews at issue in this dispute;
(c) finds it unnecessary, for purposes of resolving this dispute, to make an additional
finding on Mexico's claim that simple zeroing in periodic reviews is, as such, and as
applied in the five periodic reviews at is sue in this dispute, inconsistent with
Article 2.4 of the Anti-Dumping Agreement , and on Mexico's related claim under
Article 11 of the DSU; and
(d) does not make
 an additional finding that the Panel failed to discharge its duties under
Article 11 of the DSU by making findings that contradict those in previous Appellate
Body reports adopted by the DSB.
166. The Appellate Body recommends that the DS B request the United States to bring its
measures, found in this Report, and in the Panel Repor t as modified by this Report, to be inconsistent
with the GATT 1994 and with the Anti-Dumping Agreement , into conformity with its obligations
under those Agreements.

Signed in the original in Geneva this 4th day of April 2008 by:

A.V. Ganesan
Presiding Member

 _________________________ _________________________
 Lilia R. Bautista Giorgio Sacerdoti
 Member Member

ANNEX I

4 February 2008

(08-0497)
 Original: Spanish

Notification of an Appeal by Mexico under Article 16.4 and Article 17 of the Understanding

on Rules and Procedures Governing the Settlement of Disputes (DSU) and
Rule 20(1) of the Working Procedures for Appellate Review

 The following notification dated 31 January 20 08, from the delegation of Mexico, is being
circulated to Members.

 Pursuant to Articles 16.4 and 17 of the Understanding on Rules and Procedures Governing
the Settlement of Disputes (DSU) and Rule 20(1) of the Working Procedures for Appellate Review ,
Mexico hereby notifies its decision to appeal to th e Appellate Body certain issues of law covered in
the Panel Report on
(WT/DS344/R) (Panel Report), and certain legal in terpretations developed by the Panel in this
dispute.

 At issue is "simple zeroing," whereby the Unite d States investigating authorities, in a periodic
review, compare individual export transactions agai nst average normal values and do not fully take
into account the results of comparisons where the export price exceeds the average normal value when
such results are aggregated in order to calculate the exporter's or producer's margin of dumping for the
product under consideration.
1

 In making its findings and conclusions regardi ng simple zeroing, the Panel failed to interpret
the relevant provisions of the General Agreement on Tariffs and Trade 1994 (GATT 1994) and the
Agreement on Implementation of Article VI of the General Agreement on Tariffs and Trade 1994
(Anti-Dumping Agreement ) in accordance with the customary rules of interpretation of public
international law as required by Articles 3.2 an d 11 of the DSU and Article 17.6(ii) of the Anti-
Dumping Agreement. In particular, the relevant interpretati ons set out in the Panel Report are at odds
with the rules of treaty interpretation in Articles 31 and 32 of the Vienna Convention on the Law of
Treaties.

1 See Panel Report, paragraphs 7.7 and 7.84-7.97.

 Mexico seeks review by the Appellate Body of the following:

1. The Panel's findings and conclusions that "sim ple zeroing" in periodic reviews is "as such"
not inconsistent with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 9.3 of the
Anti-Dumping Agreement .
2 These findings and conclusions are based on an erroneous
interpretation and application of these provisions. In particular, the Panel erred in finding
that:

 (i) Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-
Dumping Agreement do not require, for purposes of periodic reviews, that "dumping"
and "margins of dumping" be determined for the "product" under investigation as a
whole and, instead, permit a determin ation of dumping for individual export
transactions
3;

 (ii) Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-
Dumping Agreement , do not require, for the purposes of periodic reviews, that
"dumping" and "margins of dumping" be determined for each exporter and producer
subject to the proceeding and, instead, permit a determination of dumping for
individual importers or import transactions
4; and

 (iii) Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1 and 9.3 of the Anti-
Dumping Agreement, do not prohibit simple zeroing in periodic reviews.
5

2. The Panel's findings and conclusions that "sim ple zeroing" in periodic reviews is "as such"
not inconsistent with Article 2.4 of the Anti-Dumping Agreement.
6 This conclusion is based
on an erroneous interpretation and application of Articles VI:1 and VI:2 of the GATT 1994
and Articles 2.1 and 9.3 of the Anti-Dumping Agreement, as described in paragraph 1.7

3. The Panel's findings and conclusions that by applying simple zeroing in the five periodic
reviews on Stainless Steel Sheet and Strip in Coils from Mexico identified by Mexico in its
request for establishment of a panel, the U.S. Department of Commerce (USDOC), did not act
inconsistently with Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4 and 9.3 of
the Anti-Dumping Agreement.
8 This conclusion is based on an erroneous interpretation and
application of these provisions, as described in the above paragraphs.

4. The Panel's findings and conclu sions that directly contradict those in adopted Appellate Body
reports and force a WTO Member to appeal findings and conclusions that have already been
specifically overturned on appeal. In the par ticular circumstances of this dispute, such
findings and conclusions are inconsistent w ith the function of the Panel which, under
Article 11 of the DSU, is to assist the Dispute Settlement Body (DSB) in discharging its
responsibilities under the DSU. Underlying tho se responsibilities are Articles 3.2 and 3.3 of
the DSU which establish that the WTO dispute se ttlement system is a "central element in
providing security and predictability" and that the "prompt settlement of situations" is
"essential to the effective functioning of the WTO".

2 See Panel Report, paragraphs 7.145, 7.149, and 8.1(c).
3 See, for example, Panel Report, paragraphs 7.117 to 7.123.
4 See, for example, Panel Report, paragraphs 7.124 to 7.128.
5 See Panel Report, paragraphs 7.129-7.143 and 7.146-7.148.
6 See Panel Report, paragraphs 7.145 and 8.1(c).
7 See Panel Report, paragraph 7.145.
8 See, for example, Panel Report, paragraphs 7.149 and 8.1(d).

5. The Panel's failure to consider in their entiret y the claims presented by Mexico relating to the
inconsistency of zeroing with Article 2.4 of the Anti-Dumping Agreement. By failing to fully
address these claims the Panel failed to make an objective assessment of the matter before it
as required by Article 11 of the DSU.

 Mexico considers that the Panel erred in law in the interpretation and application of
Articles VI:1 and VI:2 of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping
Agreement and acted inconsistently with Article 11 of the DSU. Mexico requests that, upon reversal
of the Panel's erroneous findings and conclusions id entified above, the Appellate Body resolve this
dispute promptly by finding that simple zeroing is "as such" inconsistent with Articles VI:1 and VI:2
of the GATT 1994 and Articles 2.1, 2.4, and 9.3 of the Anti-Dumping Agreement, and that the United
States violated these provisions by applying simple ze roing in the five periodic reviews identified by
Mexico.