In general, the rules of the World Trade Organization (WTO), of which the United States is a member, require each member to apply tariffs and duties equally to all other members. This principle, known as unconditional most-favored-nation (MFN) treatment, has been central to the rules-based global trading system since 1947 and part of U.S. law and foreign policy since 1922. The WTO agreements allow exceptions to this treatment in certain circumstances, including to remedy unfair trade practices and to help domestic industries adjust to sudden surges of fairly traded goods. The three most frequently applied U.S. trade remedy laws permit the imposition of antidumping duties, countervailing duties, and safeguards. These laws are enforced through administrative investigations and actions of two U.S. government agencies: the International Trade Administration of the Department of Commerce (ITA) and the U.S. International Trade Commission (USITC). The most commonly used of these remedies are antidumping (AD) laws. AD laws provide relief to domestic industries that have been, or are threatened with, material injury caused by imports sold in the U.S. market at prices that are shown to be less than fair value. The relief provided is an additional import duty, calculated by the ITA and placed on the dumped imports. Antidumping orders are the most frequently used and the most controversial trade remedy. In general, dumping occurs when manufacturers export goods for less than they sell similar goods in their domestic market. The controlling international agreement in the World Trade Organization (WTO) â the Antidumping Agreement (ADA) â defines dumping as the introduction of a product "into the commerce of another country at less than its normal value, if the export price of the product exported from one country to another is less than the comparable price, in the ordinary course of trade, for the like product when destined for consumption in the exporting country." U.S. law similarly defines dumping as the "sale or likely sale of goods [in the United States] at less than fair value," with the fair value defined as "the price at which the foreign like product is first sold â¦ for consumption in the exporting country." Simply put, dumping is the sale of goods abroad for less than the price the goods would have commanded in the home market. Economists have long written about the practice of selling exports for a lower price than in the home market. In 1776, Adam Smith noted the practice by manufacturers to export some of their surplus goods for sale at a loss for the purpose of "[doubling] the price of their goods in the home market." Several years later, Alexander Hamilton expressed concern with the practice and its potential to stymie the development of domestic industry. However, such mentions were sporadic and generally isolated to economic treatises. As more countries industrialized in the late-nineteenth century, exporting goods for a price below the price that could be commanded in the domestic market (whether at a loss or not) became an economic strategy used to maintain domestic prices while establishing footholds in foreign markets. The expansion of these practices resulted in more sustained scholarly and political attentionânot all negative. In 1880, for example, the U.S. Secretary of State encouraged cotton manufacturers to "sacrifice profits for a time, if necessary, to secure trade-standing in â¦ several markets." Twenty-five years later, the U.S. Department of Commerce and Labor was still dispensing similar advice to manufacturers. Because of this strategic deployment of dumping, and the reemergence of state-directed trade policies at the turn of the twentieth century, politicians and the public (if not always the economists) began to argue that the practice was unfair. Accusations of using foreign markets as "dumping-grounds" became frequent and the term "dumping" to describe the practice of selling surplus goods abroad at a lower price began to be used more frequently. British industrialists protested dumping from German and French manufacturers, while Canadian millers grumbled about the dumping of American steel. While accusations of dumping were common, the actual prevalence of the practice is hard to calculate, in part because there was no administrative apparatus to investigate such complaints. Nevertheless, experts generally agree that there was, in fact, at least a modest increase in the practice. There were several possible causes for whatever dumping existed at the time. First, higher tariffs in general encouraged the practice. As a leading scholar of antidumping has argued, "These tariffs provided national firms the opportunity to price monopolistically at home and at the same time protected them from reimports of goods they sold competitively abroad." Other observers have noted that dumping was, in some respects, a natural development of trade in industrially advanced countries as large manufacturers attempted to offset changes in domestic demand by selling large surpluses abroad. During the first decades of the twentieth century, countries began to take action to prevent dumping or, at least, protect their domestic industries from dumping. In 1904, Canada enacted the world's first modern antidumping (AD) law. By 1921, Australia, New Zealand, South Africa, France, Japan, the United States, and Britain had proposed or enacted AD statutes or other legislation giving administrative officials discretion to alter tariffs in response to influxes of goods at abnormally low prices. Many of the statutes, including the American, were modeled on the Canadian law. The Economic and Financial Section of the League of Nations Secretariat (the precursor to the United Nations) also commissioned studies on the issue to survey AD legislation and see if there was a need for international regulation. U.S. AD law had precursors in late-nineteenth-century antitrust legislation. Some early observers argued that dumping was a strategy used to injure or hinder development and maintain monopolistic dominance over foreign countries. In 1916, Congress passed the Antidumping Act, which imposed criminal and civil penalties on any person importing and selling articles in the United States "at a price substantially less than the actual market value or wholesale price of such articles" so long as they had the intent of injuring or preventing the establishment of an industry in the United States. The law was rarely applied, in part because it was difficult to prove such an intent. U.S. antidumping law took its modern form with the passage of the Antidumping Act of 1921, which adopted a more globally common administrative (rather than judicial) procedure that enabled the imposition of additional duties on imports rather than civil or criminal penalties (as the antitrust branch of legislation had). The Antidumping Act of 1921 became the textual basis for Article VI of the General Agreement on Tariffs and Trade (GATT) in 1947, the multilateral trade agreement that established the post-World War II rules-based trading system and which was later incorporated into the World Trade Organization (WTO) agreements. As such, the U.S. model of antidumping has become the global standard. Since 1921, Congress has amended and adjusted U.S. antidumping law many times, but has maintained the basic administrative framework and Article VI was clarified and amended by the ADA as part of the establishment of the WTO in 1995. Statutory authority for AD investigations and remedial actions is found in Subtitle B of Title VII of the Tariff Act of 1930, as amended (codified, as amended, at 19 U.S.C. Â§Â§1673 et seq .). The law requires the imposition of an antidumping duty if (1) the International Trade Administration of the Department of Commerce (ITA) determines that imported merchandise is being, or likely to be, sold in the United States at less than fair value; and (2) the U.S. International Trade Commission (USITC) determines that an industry in the United States is materially injured or is threatened with material injury, or that the establishment of an industry is materially retarded, by reason of imports of that merchandise. The statute requires that the AD duty equal the amount by which the normal value (a calculation of the fair value) of the merchandise exceeds the export price of the merchandise. The United States is a party to several international agreements that govern the use of AD laws, including Article VI of the General Agreement on Tariffs and Trade (GATT), which was incorporated into the agreements establishing the WTO, and the WTO's Antidumping Agreement (ADA). Both of these agreements were based upon U.S. AD law and practice and the United States was a proponent of both agreements. All WTO members are subject to the terms of Article VI of the GATT and the Antidumping Agreement. Article VI of GATT allows the imposition of antidumping duties in cases where dumping "causes or threatens material injury to an established industry in the territory of a contracting party or materially retards the establishment of a domestic industry." The ADA elaborates on the basic principles established in Article VI of the GATT by providing more detail on several issues, including how WTO members may determine whether dumping is occurring, how they determine whether there has been an injury to a domestic industry, what kinds of evidence can be used, and other issues. WTO members whose antidumping laws or practices violate the terms of the ADA may be subject to WTO dispute settlement proceedings. The ITA initiates antidumping investigations either on its own initiative or in response to a petition filed by a representative of a domestic industry with the USITC and the ITA. If the ITA receives a petition, it must normally initiate an investigation within 20 days after it receives a petition and determines that the petition contains the necessary elements for imposing a duty. The USITC begins the investigation. The central question of its investigation is whether there is a reasonable indication of an injury or likely injury to a domestic industry. If the USITC's preliminary determination is negative or the USITC determines that imports of the subject merchandise are negligible, then proceedings end. In most circumstances, the USITC must make a preliminary determination no later than 45 days after the start of the investigation. If the USITC's preliminary determination is affirmative, then the ITA begins its preliminary investigation to determine whether dumping exists. The ITA must make its determination within 140 days, or within 190 days at the petitioner's request or if the case is extraordinarily complicated. If the ITA's preliminary determination is affirmative, then ITA also estimates a weighted-average dumping margin for each exporter or producer individually investigated and an "all-others rate" for all other exporters. The ITA publishes its preliminary results in the Federal Register and orders U.S. Customs and Border Protection (CBP) to delay the final computation of all duties on imports of the targeted merchandise ("suspend liquidation") until the case is resolved and to require the posting of cash deposits, bonds, or other appropriate securities to cover the duties (plus the estimated dumping margin) for each subsequent entry into the U.S. market. If the ITA's determination is negative, the ITA continues the investigation to the final stage (without ordering a suspension of liquidation) and the USITC continues its investigation as well. Because this is a preliminary determination, agencies may not have obtained all possible evidence, and this allows interested parties a final opportunity to put information and evidence before the two bodies. Generally, the ITA must make its final determination within 75 days of the preliminary determination. Before issuing a final determination, the ITA must hold a hearing upon request of any party to the proceeding. If the ITA's final determination is negative, the proceedings end, and any suspension of liquidation is terminated, bonds and other securities are released, and deposits are refunded. If the ITA's final determination is affirmative, it orders the suspension of liquidation if it has not already done so. The ITA will publish the order in the Federal Register and direct CBP to continue or resume (if provisional measures expired) suspension of liquidation and collection of cash deposits at the rate determined in the ITA's final determination. Congress enacted the critical circumstances provision in order "to provide prompt relief to domestic industries suffering from large volumes, or a surge over a short period, of imports and to deter exporters whose merchandise is subject to an investigation from circumventing the intent of the law by increasing their exports to the United States during the period between initiation of an investigation and a preliminary determination by the [ITA]." If a petitioner alleges that critical circumstances exist in an antidumping case (which would impose additional retroactive AD duties that one would not normally obtain), then the ITA determines whether: (1)(a) there is a reasonable basis to suspect that there is a history of dumping (combined with material injury due to the imports), or (b) that the importer knew or should have known that the exporter was selling the merchandise at less than fair value, and also knew that there was likely to be material injury due to the sales; and (2) whether massive imports of the merchandise have occurred over a relatively short period. If the ITA makes an affirmative critical circumstances finding, it extends the suspension of liquidation of any unliquidated entries of merchandise (entries for which estimated AD duties have not been paid) into the United States retroactively to 90 days before the suspension of liquidation was first ordered or the date on which notice of the determination to initiate the investigation is published in the Federal Register, whichever is later. Whether or not the ITA's initial critical circumstances determination is affirmative, if its final determination on subsidies or dumping is affirmative, the ITA must also include a final determination on critical circumstances. If the final determination on critical circumstances is affirmative, retroactive duties, if not yet ordered, are ordered on unliquidated entries at this time. If the critical circumstances determination is negative, all retroactive suspension of liquidation is terminated, and bonds, securities, or cash deposits related to the retroactive action are released. If the ITA makes an affirmative determination of critical circumstances, the USITC's final determination must include a finding as to whether the subject imports are likely to undermine seriously the remedial effect of the AD order. If both the USITC and the ITA make affirmative critical circumstances determinations, any AD duty order applies to the goods for which the retroactive suspension of liquidation was ordered. If the final critical circumstances determination of either agency is negative, any retroactive suspension of liquidation is terminated, bonds and securities are released, and any cash deposits are refunded. The ITA or the USITC may terminate an investigation if the petitioner withdraws the petition or of its own accord if the ITA self-initiated the investigation. Additionally, the ITA may, in certain circumstances, suspend an antidumping investigation in favor of an agreement with foreign exporters (known as "suspension agreements") that either eliminates the sales of less than fair value or the injurious effect. One example of such an agreement is the recent suspension agreement between the various Mexican growers associations and the United States with respect to fresh tomatoes. The United States agreed to suspend its antidumping investigation in exchange for a promise by various Mexican growers associations accounting for substantially all imports of fresh tomatoes from Mexico not to sell fresh tomatoes in the United States at a price less than an established reference price. Each year, during the anniversary month of the publication of a final AD order, any interested party may request an administrative review of the order. The ITA may also self-initiate a review. During the review process, the ITA recalculates the dumping margin and may adjust the amount of AD duties on the subject merchandise. Suspension agreements are also monitored for compliance and reviewed in a similar fashion. The ITA must make a preliminary determination within 245 days after the last day of the anniversary month of the order or suspension agreement under review, and must make a final determination within 120 days after the publication date of a preliminary determination. New exporters, who were not part of the original review, may also request an expedited review. An interested party may also request a "changed circumstances" review from the ITA or the USITC at any time. Under current regulations, upon receipt of such a request, the ITA must determine within 45 days whether to conduct the review. If the ITA decides that there is good cause to conduct the review, the results must be issued within 270 days of initiation, or within 45 days of initiation if all interested parties agree to the outcome of the review. Sunset reviews must be conducted on each AD order no later than once every five years after its publication. In such a review, the ITA determines whether dumping would likely continue or resume if an order were to be revoked or a suspension agreement terminated, and the USITC conducts a similar review to determine whether injury to the domestic industry would be likely to continue or resume. If both determinations are affirmative, the duty or suspension agreement remains in place. If either determination is negative, the order is revoked, or the suspension agreement is terminated. During the first two decades of the GATT, countries infrequently imposed antidumping measures. Only four partiesâthe United States, the European Union (EU), Canada, and Australiaâmade use of the practice, and even that was infrequent. Scholars have given several non-exclusive explanations for the relative dearth of antidumping measures in this period in both the international and U.S. contexts. In the international context, ambiguity within Article VI of the GATT may have discouraged GATT members from making use of the antidumping provisions. Specifically, Article VI does not specify a methodology for deciding whether a product is dumped nor does it set out procedures for AD investigations. Additionally, tariff rates among GATT members were still relatively high, which may have dampened the need for industries to petition for protection through antidumping measures. Likewise, in the United States, the Antidumping Act of 1921 was enacted during a period when tariff rates were relatively high, which may have limited the usefulness of AD duties as a form of protection. Administrative exigencies may have also been a factor. For example, one historian has noted that the Carter Administration shifted responsibility for making the less than fair value determination from the Treasury Department to the Department of Commerce because the "perceived indifference of Treasury to the plight of petitioning firms" may have led to fewer findings of dumping and thus fewer measures. Finally, countries, particularly those who were not GATT signatories, had higher average tariff rates and were able to impose other non-tariff barriers to trade to reduce importation of allegedly dumped products, which made resorting to AD measures unnecessary. Over the subsequent decades, dozens of developing countries entered the rules-based trading order, which restricted the use of many non-tariff barriers to trade and encouraged the reduction of tariffs. The reduction of tariffs may have led to an increase in the use of AD measures as an alternative form of protection. AD investigations and actions were uncommon in the decades following the establishment of the GATT. Before the 1990s, the United States, the European Union, Canada, and Australia were responsible for more than 95% of AD actions. Many developing countries did not even have AD laws and procedures. Beginning in the 1990s, however, the number of countries with AD laws multiplied; approximately half of all AD laws in effect today were implemented after 1990. With the increase in the number of countries with AD laws, the major users of AD measures have changed dramatically. In 1994, for instance, India had zero AD measures in force. Twenty-five years later, in 2019, India had 275 AD measures in force, ranking second behind the United States. Between 2008 and 2018, India ranked first in terms of the number of AD measures imposed per year, followed by the United States, Brazil, China, and Argentina. Of the top five users of AD measures prior to 1995, only the United States remains in that top five (see Table 2 ). However, if adjusted for per-dollar imports, both the United States and the EU are relatively light users of AD measures. As more countries have begun to use AD measures, the total number of AD measures in force has increased by more than 600%, jumping from 264 measures in force in 1994 to 1,860 in 2018. Many of the largest users of AD investigations and measures are also among the top targets of AD investigations and measures. China, the United States, and India, are among the top users of AD investigations and measures and are, likewise, the top targets of AD investigations and measures. AD measures are imposed primarily on heavy industrial products from the base-metal and chemical industries. Figure 4 . The adoption of AD laws and the imposition of measures generally occur following moments of increased market integration and trade liberalization, which may explain their expanded use. In effect, AD measures blunt the impact of new imports. For example, many developing countries reduced their tariffs significantly following the Uruguay Round of trade negotiations, which created the WTO. With significantly lower tariffs and fewer other means available to restrict trade, developing countries (like their developed counterparts before them) may have turned to AD laws and AD measures as a preferred means of protecting select domestic industries during their adjustment to the lower average tariff rate. For example, since their entry into the WTO, India, Brazil, China, and Argentina have collectively reduced their tariffs by an average of 63% from a 17.6% applied weighted mean for all products to 6.5%. In that same time, those four countries increased their use of AD measures dramatically. In 1995, those countries had 13 measures in force. By 2018, they had a total of 646 measures in force, an increase of more than 4,800%. Figure 5 . As for AD measures being used rather than some other trade remedy, at least one scholar has argued that AD measures are the most attractive alternative legal form of contingent protection. In general, AD measures are easier to impose. As of February 2020, the United States has 384 AD orders in place affecting imports from 53 countries. The oldest order, which places AD duties on pressure sensitive tape from Italy, has been in place continually since 1977. Seventy-five of the orders have been in place since before the turn of the millennium. The United States is alone among the original four users of AD measures (U.S., EU, Canada, and Australia) in significantly increasing its use of AD measures over the past two decades. The U.S. currently has the highest number of AD measures in force in its history. In comparison, the other three original users have kept the number of measures in force at or below levels reached around the millennium. The United States has been a frequent target of AD investigations initiated by other countries. Between 1995 and 2017, the United States was the target of 296 investigations, 181 (61%) of which led to the imposition of AD measures. The largest user of AD measures against the United States is China (37), with India (30), Brazil (24), Mexico (23), and Canada (12) rounding out the rest of the top five. The reasons for the targeting of the United States are uncertain. They may, however, relate to the use of AD measures as a form of protection during a period of trade liberalization or be viewed as retaliation for the United States' heavy use of AD measures against these countries. Some argue that antidumping measures constitute "the first and best line of defense for the U.S. economy against companies and countries that resort to predatory and mercantilist tactics to make trade gains." Most empirical research, however, has found such predatory pricing is rare. Furthermore, most academic analysts are highly critical of U.S. AD law and practice. Economic analysts in particular note that AD policy is trade distorting. For example, AD duties deflect trade, by causing exporters to seek out markets where their goods are not subject to AD duties. As one pair of economists noted, the suspension agreement on fresh tomatoes from Mexico caused Mexico to make more tomato paste to ship to the United States and to ship more fresh tomatoes to Canada, which in turn shipped more fresh tomatoes to the United States. Many scholars also conclude that AD duties depress consumer activity by raising costs for consumers and propping up unproductive businesses. According to one survey, AD policies globally affect somewhere between 3% and 8% of a country's total imports, making them one of the most costly commercial policies. There is also a general consensus that AD duties, when analyzed economically without consideration of their political benefits for encouraging trade liberalization, depress overall trade. Congress has generally been supportive of AD duties, and reform efforts have been limited despite the generally negative view of the practice held by many economists. Phillip Swagel, the now-director of the Congressional Budget Office and former Assistant Secretary of the Treasury for Economic Policy, recently referred to antidumping as the "third rail of trade policy," arguing that "few politicians of either party [are] willing to point out its broadly negative impact." While many argue that AD laws are economically inefficient if evaluated on their face, some of those critics have conceded "that even if AD is the largest and most frequently used contingent trade remedy (and the most costly single commercial policy), AD may nevertheless be a desirable policy as it serves an important role in promoting overall trade liberalization by acting as a pressure release valve." As Congress considers its overall goals with respect to trade policy, it might weigh dumping's economic costs against its potential role in supporting trade liberalization. Congress could, for example, encourage (in committee hearings) or direct (through legislation) Commerce to change the de minimis thresholds for finding that dumping has taken place or that the dumped goods have caused an injury. Such changes could reduce or encourage the use of the policy. During the negotiations over the establishment of the WTO, the United States persistently advocated for the establishment of robust dispute settlement provisions and Congress required the President to ensure that dispute resolution provisions were included in the final agreement. As a result, the agreements establishing the WTO included the Dispute Settlement Understanding (DSU), which provides for an enforceable means by which members can resolve disputes over WTO commitments and obligations. In recent years, however, several administrations have been critical of the WTO's dispute settlement system in general and with the role of the Appellate Body (AB) in particular. In December, the AB ceased to function as the United States continued to block the appointment of new AB members to replace those whose terms had expired. U.S. AD policies have been at the center of that dispute and Congress might consider reevaluating those policies or renegotiating the agreement underlying the WTO DSU and ADA if it wishes to maintain a functional dispute settlement system at the WTO. The United States has generally been successful in DSU proceedings with the exception of one areaâtrade remedies. Indeed, trade remedy cases in general make up the largest portion of the WTO's dispute settlement docket, with AD being the most frequently disputed policy. Time and time again dispute settlement (DS) Panels and the AB have found U.S. AD policy to conflict with its international commitments. The United States is not alone. Other WTO members have also been unsuccessful in defending challenges to their implementation of the ADA. The AD policy that has been at the center of many (although not all) of these disputes is a calculation method referred to as "zeroing." In general, when calculating the dumping margin to determine whether the imposition of antidumping measures on exporters of a product is justified, the ITA will usually average together numerous comparisons between sales in the United States (the export prices) and sales in the home market (the normal value). The ITA will aggregate hundreds or even thousands of individual transactions together in this process. The amount by which the normal value exceeds the export price of a given product is the dumping margin. However, if the export price exceeds the normal value (that is, if the price in the United States is greater than the domestic price) and thus produces a negative result, the United States, in certain circumstances, will adjust the negative values to zero. As an economist at the Department of Justice put it, "The use of 'zeroing' will almost always increase the level of any antidumping duty, and will sometimes create a duty where none would have been imposed, had the methodology not been used." Consider the following simplified example: the average home market price and export price for a product for the entire month were both $100. As such, the dumping margin and weighted average dumping margin when averaged without zeroing were both zero because the transaction on September 7, for example, was offset by the transaction on September 25. However, when zeroing is applied, the September 25 transaction is set to zero. When this is applied across all values, the aggregate dumping margin is $55 leading to a weighted average dumping margin of 7.85%. One pair of economists determined in 2010 that if the United States were to stop zeroing, "then perhaps as much as half of all U.S. AD measures would be removed and the duties in the other cases would fall significantly." The U.S. Trade Representative (USTR) asserts that this method allows the United States to "focus on those transactions in which dumping occurs." Under the relevant WTO agreements, the USTR argues, "Members may calculate a margin of dumping on a transaction-by-transaction basis, and, thus, collect duties only on dumped imports, while collecting no duties on non-dumped imports. There is no requirement to offset dumped transactions with transactions in which dumping did not occur." The U.S. Trade Representative has asserted that this is a common-sense method of calculating the extent of dumping that is injuring a domestic industry" and that the elimination of zeroing "artificially reduces the margin of dumping," Opponents of zeroing argue that its effect is to artificially increase dumping margins and increase the likelihood that AD measures will be imposed. Specific concerns include that "zeroing makes it extremely difficult for a firm to avoid dumping" because the reasons for price variation, such as seasonality, exchange rates, and variations in shipping costs, are not taken into account. As a result, products subject to greater price variation will be more frequently subject to AD duties. As the United States is the only country to actively zero, it seems unlikely that zeroing is strictly necessary to ensure that AD policy is effective at preventing dumping. One economist estimated in 2008 that "zeroing could add perhaps 3-4 % to the typical U.S. antidumping duty with a cost to the U.S. of around $150 million per year when all existing U.S. antidumping orders were determined by zeroing." Since 1995, more than 30 Panel and Appellate Body (AB) decisions have found the use of zeroing in specific AD investigations to be inconsistent with the ADA; the AB has held more than a dozen times that zeroing in one form or another cannot be used. In all but two cases involving zeroing, the United States has been the respondent. In two early cases, the EU was the respondent, but it changed its practices after the AB found its implementation of the practice to be inconsistent with the terms of the ADA. The United States has been a respondent in more than 150 disputes before the WTO. Fifty-six of those involved the ADA and many of those cases involved zeroing. In all the finalized cases, the United States lost or settled. Indeed, CRS analysis has found that nearly half of all cases where the WTO found a U.S. practice to not be in compliance with WTO obligations involved dumping. Much of the U.S. criticism levied at the WTO's AB over the past decade, some have argued, has been primarily the result of cases involving U.S. implementation of the ADA. In a recent report listing U.S. concerns about the AB, the USTR identified six areas of "Appellate Body errors in interpreting WTO agreements" that it argues have "raised substantive concerns and undermine the WTO." Five of the six concerned trade remedies, including dumping. Indeed, "dump" was the most common trade-related verb in the report. With respect to zeroing, the USTR argues, "The Appellate Body's invention of a prohibition on the use of "zeroing" to determine dumping margins has diminished the ability of WTO members to address dumped imports that cause or threaten injury to a domestic industry." The WTO AB's approach to trade remedies in general, and antidumping in particular, have been central in USTR's critique of the AB and thus has likely played a significant role in its decision to block appointments to the AB. However, WTO DSB debates are not over. The USTR has approvingly cited a recent DSB decision that upheld the use of zeroing in certain limited circumstances. As Congress considers the future U.S. relationship with the WTO and the multilateral rules-based trading order, it might address the role that antidumping has played in straining that relationship. For example, Trade Promotion Authority (TPA) expires in 2021. Should Congress decide to reauthorize TPA, it may choose to direct the President to seek revisions to the WTO's DSU of the ADA to address some of these issues. Alternatively, Congress could encourage or direct Commerce to address some of the WTO members' and Appellate Body's concerns. For example, the EU and Canada once employed zeroing in antidumping investigations, but no longer do so.

Summary: The U.S. Constitution grants to Congress the power to regulate trade with foreign nations and levy tariffs. Since 1922, U.S. law and foreign policy have favored applying tariffs and duties equally to all trading partners. This principle, known as most-favored-nation (MFN) treatment, has been central to the rules-based global trading system since 1947. One of the most frequently invoked exceptions to MFN treatment are three "trade remedy" laws. These laws are enforced primarily through administrative investigations of two U.S. government agencies: the International Trade Administration of the Department of Commerce (ITA) and the U.S. International Trade Commission (USITC). Trade remedy laws enable the United States to impose additional duties aimed at specific producers or countries to remedy unfair trade practices and to help domestic industries adjust to sudden surges of fairly traded goods. The three types of laws traditionally classified as "trade remedies" are: Antidumping (AD) laws provide relief to domestic industries that have been, or are threatened with, material injury caused by imported goods sold in the U.S. market at prices that are shown to be less than fair market value. The relief provided is an additional import duty placed on the dumped imports based upon calculations made by the ITA. Antidumping orders are the most frequently used and the most controversial trade remedy. Countervailing duty (CVD) laws give a similar kind of relief to domestic industries that have been, or are threatened with, material injury caused by imported goods that have been found to have received WTO-inconsistent government subsidies, and can therefore be sold at lower prices than similar goods produced in the United States. The relief provided is an additional import duty placed on the subsidized imports. Safeguard (also referred to as escape clause) laws give domestic industries relief from surges of imported goods that are fairly traded if serious injury is found or is threatened to the domestic industry. The most frequently applied safeguard law, Section 201 of the Trade Act of 1974, is designed to give domestic industry the opportunity to adjust to the new competition and remain competitive. The relief provided is generally an additional temporary import duty, a temporary import quota, or a combination of both. Safeguard laws also require presidential action in order for relief to be put into effect. Economists have generally seen antidumping laws and policies as economically inefficient. Some, however, have acknowledged the role that these economically inefficient policies have played in making trade liberalization more politically feasible by providing protection for industries that might otherwise oppose such measures. In recent years, U.S. exports have increasingly become a target of AD measures by several major emerging economies, including India and China. Antidumping laws and policies have also been at the center of dozens of trade disputes between the United States and its trading partners in the WTO. Reports issued by the WTO's Appellate Body (AB) on the subject have been one of the primary targets of the U.S. Trade Representative's criticisms of the AB mechanism in the broader WTO dispute settlement system. If Congress wishes to maintain a functional dispute settlement system at the WTO it may consider either directing the President to seek amendments to underlying WTO agreements such that U.S. practices are internationally compliant or direct the ITA to bring its AD policies into conformity with the AB's interpretation of the WTO's Antidumping Agreement.