United States 

Department 

of Agriculture 

www.ers.usda.gov 

 A Report from the Economic Research Service

The Renewable Identifi cation 

Number System and 

U.S. Biofuel Mandates

Lihong McPhail, lmcphail@ers.usda.gov

Paul Westcott, westcott@ers.usda.gov

Heather Lutman*

Abstract

The Renewable Fuel Standard (RFS) sets annual mandates for renewable transportation fuels sold or introduced into commerce in the United States. The current RFS 

sets mandates through 2022. The Renewable Identifi cation Number (RIN) system was 

created by the U.S. Environmental Protection Agency to facilitate compliance with the 

RFS. A RIN is a 38-character numeric code that corresponds to a volume of renewable 

fuel produced in or imported into the United States. RINs remain with the renewable 

fuel through the distribution system and ownership changes. Once the renewable fuel 

is blended into a motor vehicle fuel, the RIN is no longer required to remain with the 

renewable fuel. Instead, the RIN may then be separated from the renewable fuel and 

used for RFS compliance, held for future compliance, or traded. The RFS mandates are 

prorated down to “obligated parties”—individual gasoline and diesel producers and/

or importers—based on their annual production and/or imports. Each year, obligated 

parties are required to meet their prorated share of the RFS mandates by accumulating 

RINs, either through fuel blending or by purchasing RINs from others. Understanding 

the RIN system and the prices for RINs when bought and sold can provide key insights 

into the impact of mandates on biofuel and feedstock markets. For 2011, conventional 

ethanol RIN prices have been low, implying low probability that the corresponding 

mandate has been binding and suggesting that other factors have contributed to expansion beyond the mandate. Conversely, biodiesel RIN prices have been high in 2011, 

implying a more binding biodiesel mandate with effects on soybean oil and other 

biodiesel feedstock markets. 

Keywords: Renewable Fuel Standard, Renewable Identifi cation Number, mandates, 

biofuels, feedstocks

*Formerly an agricultural economist with USDA’s Economic Research Service, Lutman is now a farm 

loan offi cer with USDA’s Farm Service Agency.

BIO-03

November 2011

Contents

Approved by USDA’s 

World Agricultural 

Outlook Board

Introduction .............................. 3

Background ............................. 4

The RIN Market Is Key To 

Implementing the Renewable 

Fuel Standard .......................... 7

U.S. Conventional 

Ethanol Market ...................... 14

U.S. Biodiesel Market ............ 17

Outlook and Implications ....... 21

References ............................ 23
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Acknowledgments

We thank Erik Dohlman, Thomas Capehart, Molly Garber, Allen Baker 

(USDA, Economic Research Service); Harry Baumes and James Duffi eld 

(USDA, Offi ce of Energy Policy and New Uses); Wyatt Thompson and Seth 

Meyer (University of Missouri); and Bruce Babcock (Iowa State University) 

for their comments and suggestions. The report was cleared by Jerry Norton 

and Keith Menzie at the World Agriculture Outlook Board. The authors also 

thank Angela Anderson for editorial assistance. 
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To reduce dependence on foreign oil and to address climate change 

concerns, U.S. policymakers have introduced a combination of policies to support the production and consumption of biofuels. An important element of U.S. biofuel policy is the Renewable Fuel Standard 

(RFS). The RFS originated with the Energy Policy Act of 2005 and was 

expanded and extended by the Energy Independence and Security Act of 

2007 (EISA). The Renewable Identifi cation Number (RIN) system was 

developed by the U.S. Environmental Protection Agency (EPA) to ensure 

compliance with RFS mandates. RINs are used by obligated parties to 

demonstrate compliance with their pro rata share of a particular year’s 

mandate. Obligated parties are producers or importers of gasoline and 

diesel in the 48 contiguous States and Hawaii, including blenders that 

produce gasoline from nonrenewable blendstocks.1 Understanding the 

RIN market is key to understanding the role of the RFS mandates in 

biofuel and feedstock markets.

 1Noncontiguous States and territories 

are not specifi cally included, but Hawaii 

has chosen to opt in to the program. 

Also, some exceptions have been provided for small refi neries. 

Introduction
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Over the years, policymakers have introduced different policies to support the 

production and consumption of biofuels (Duffi eld et al., 2008). The National 

Energy Act of 1978 gave ethanol blends of at least 10 percent in volume a 

40-cent-per-gallon exemption from the Federal motor fuel tax. 

The Clean Air Act Amendments of 1990 (CAAA 90) boosted demand for 

ethanol. Congress mandated the use of oxygenated fuels in specifi c U.S. 

regions during winter months to reduce carbon monoxide emissions. The 

two most common ways to increase the oxygen content of gasoline are 

to add methyl tertiary butyl ether (MTBE) or ethanol. As provided by the 

CAAA 90, cities with the worst smog pollution were required to use reformulated gasoline by 1995. Congress further specifi ed that reformulated 

gasoline contain oxygen at 2 percent by weight. While many cities voluntarily adopted this program, environmental concerns about MTBE led many 

States to ban its use.

The 2005 Energy Policy Act and several of its provisions related to agriculture-based renewable energy production were critical factors driving the 

surge in ethanol supply and demand. This act maintained air quality standards, thereby continuing the need for reformulated gasoline. Furthermore, 

the act did not provide liability protection for MTBE, reducing its use 

and stimulating ethanol demand (Westcott, 2007). Consequently, ethanol 

became the oxygenate of choice for the reformulated gasoline program by 

spring 2006. Indirectly, other Federal programs supported ethanol production by providing incentives for research on renewable fuels. This act also 

created the RFS program, which initially mandated that 4.0 billion gallons 

of renewable fuel be blended into gasoline in 2006 and increased to 7.5 

billion gallons by 2012.2

The scope of the RFS was expanded and extended in 2007 by the EISA. 

Provisions of the new mandate (or RFS2) go through 2022. RFS2 mandates 

inclusion of 15.2 billion gallons of renewable fuel in U.S. transportation 

fuel by 2012 and 36 billion gallons by 2022.3 Specifi c RFS2 mandates were 

created for various subcategories of biofuels—advanced biofuels, cellulosic biofuels, and biomass-based diesel (biodiesel).4 The sub-mandates are 

defi ned by eligible feedstock types and lifecycle greenhouse gas (GHG) 

emission reductions.5

The subcategory mandates also have a hierarchy within RFS2. For example, 

of the 15.2 billion gallons mandated for 2012, 2 billion gallons must come 

from advanced biofuel. RFS2 specifi es the required volumes for biodiesel 

and cellulosic biofuels, while the rest can be met by other advanced biofuels 

that satisfy the feedstock and GHG-reduction requirement. RFS2 specifi es 

500 million gallons for cellulosic biofuel and 1 billion gallons for biomassbased diesel and leaves the remaining advanced mandate unspecifi ed. 

Any excess in the cellulosic or biomass-based diesel categories can count 

toward the unspecifi ed advanced mandate. The other 13.2 billion gallons 

are accounted for by the unrestricted portion of the mandate6 (indicated by 

implicit nonadvanced biofuels, maximum, in fi g. 1). Ethanol derived from 

corn starch and other biofuels that do not qualify as “advanced” would count 

 2Credits for biodiesel were provided 

for under the 2005 Act. 

 3Waivers, reductions, and modifi cations to the RFS2 are allowed if the 

EPA determines that the standard would 

serverely harm the economy or environment, or that there is an inadequate 

domestic supply. EPA must reduce the 

cellulosic biofuel mandate if projected 

cellulosic production is below the 

mandate. Additionally, authority for 

adjusting the biomass-based diesel fuel 

mandate based on price-based considerations is provided for in the EISA.

 4Advanced biofuel is defi ned as any 

renewable fuel other than those derived 

from corn starch, which can apply to 

a variety of fuels, including biodiesel, 

cellulosic, and other alcohols.

 5The EPA is required to apply 

lifecycle GHG performance threshold 

standards to ensure that each category of 

renewable fuel emits fewer GHGs than 

the petroleum fuel it replaces. Specifi -

cally, the lifecycle GHG emissions of 

qualifying renewable fuels must be at 

least 20 percent less than the lifecycle 

GHG emissions of the 2005 baseline average of petroleum fuel that it replaces. 

Similar rules apply to renewable fuels 

qualifying as advanced biofuel (50 percent), biomass-based diesel (50 percent) 

and cellulosic biofuel (60 percent).

 6Corn ethanol qualifi es for the 

unrestricted portion of the mandate, but 

there is no specifi c mandated volume 

for corn-based ethanol in RFS2. Thus, 

corn-based ethanol use beyond the unrestricted portion of the mandate would 

not count toward meeting total RFS2.

 Background
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toward this category’s mandate. Again, the hierarchy of the submandates 

means that any excess from the advanced mandate can count toward this 

unrestricted portion, but not vice versa. 

The Renewable Identifi cation Number (RIN) system was developed by 

the EPA to ensure compliance with RFS2 mandates. A RIN is a 38-character numeric code (table 1) that corresponds to a volume of renewable 

fuel produced in or imported to the United States. RINs are generated by 

the producer or importer of the renewable fuel. RINs must remain with the 

renewable fuel as the renewable fuel moves through the distribution system 

and as ownership changes. Once the renewable fuel is blended into motor 

vehicle fuel, the RIN is no longer required to remain with the renewable fuel. 

Instead, the RIN may be separated from the renewable fuel and then can be 

used for compliance, held for future compliance, or traded. 

RINs are the basic units for RFS2 compliance. The EPA has developed a 

system called the EPA Moderated Transaction System (EMTS) to manage 

RIN transactions.7 EMTS screens RINs and provides a structured environment for conducting RIN transactions.8 To participate, users must:

1. Register with EPA; 

2. Create an individual account via EPA’s Central Data Exchange (CDX); 

and

3. Submit transactions. 

For example, a renewable fuel producer can electronically submit a volume 

of renewable fuel produced, as well as the number of RINs generated and 

assigned. EMTS will automatically screen each batch and either reject the 

information or allow the RINs created by the generator’s account. RINs must 

 7Under the initial RFS, parties made 

various errors generating and using 

RINs.

8As of July 1, 2010, renewable fuel 

producers and importers, gasoline and 

diesel refi ners, renewable fuel exporters, RIN owners, and any other RFS2 

regulated party must use EMTS.

Figure 1

Renewable fuel standard (RFS) mandate, by type, 2008-22

Note: Biodiesel RFS specified through 2012; subsequent years “shall not be less than the applicable volume. . .for calendar year 2012.”

Source: U.S. Environmental Protection Agency, Energy Independence and Security Act of 2007.

0

5

10

15

20

25

30

35

40

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Biomass-based diesel (biodiesel)

Other advanced biofuels

Cellulosic biofuels

Implicit nonadvanced biofuels (maximum)

Billion gallons

Calendar year
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remain with the biofuel until it has been blended; then it may be traded. 

The seller posts the sale of their RINs at a certain price. The buyer logs 

into EMTS and accepts the transaction, assuming all information is correct. 

Upon acceptance, the buyer’s RIN account is automatically increased by the 

number of RINs purchased. RIN transactions must be verifi ed and certifi ed 

quarterly by the EPA. The RIN price is one of the new pieces of information 

required by the EPA to be reported to the EMTS (EPA, March 2010).

Table 1

Renewable Identifi cation Number (RIN) code defi nitions

38-character code:

KYYYYCCCCFFFFFBBBBBRRDSSSSSSSSEEEEEEEE

K RIN assignment code (1=Assigned; 2=Separated)

YYYY Year batch is produced/imported 

CCCC Company registration ID

FFFFF Facility registration ID

BBBBB Producer-assigned batch number

RR Equivalence value for the renewable fuel

D Renewable type code1

SSSSSSSS RIN block starting number

EEEEEEEE RIN block ending number

1Five separate RIN categories: D=3 for cellulosic biofuel; D=4 for biomass-based diesel; D=5 

for advanced biofuel; D=6 for other renewable fuel; and D =7 for cellulosic diesel.

Source: U.S. Environmental Protection Agency.
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The RIN market plays a critical role in successfully implementing the RFS2. 

By the end of November each year, the EPA calculates an annual percentage 

RFS2 by dividing the volume of renewable fuel required by EISA to be 

blended into gasoline and diesel for the following year by the volume of 

gasoline and diesel projected to be consumed in that year according to the 

U.S. Energy Information Administration (EIA). For example, EISA set a total 

RFS2 of 13.95 billion gallons of total renewable fuel for 2011, and the EPA 

calculated the fi nal percentage standard for renewable fuel at 8.01 percent.9

The renewable volume obligation (RVO) (table 2) for each obligated party 

is equal to this percentage standard times the annual volume of gasoline and 

diesel produced or imported.

Each calendar year, obligated parties must meet their RVOs by accumulating 

RINs that represent an amount of renewable fuel used as transportation fuel 

sold or introduced into commerce in the United States. If an obligated party 

has not acquired enough RINs to meet its RVOs then, under certain conditions, the party can carry a defi cit into the next calendar year so long as the 

full defi cit and that following year’s obligation are covered in the next year. 

If an obligated party acquires more RINs than it needs to meet its RVOs, it 

can transfer the excess to another party or retain them for compliance with 

its RVOs in the following year (subject to a 20 percent rollover cap). The 

rollover cap ensures that no more than 20 percent of a current-year obligation can be satisfi ed using RINs from the previous year. These options reduce 

costs to obligated parties of meeting their RVOs. Some nonobligated parties10

(when registered with the EPA) are also allowed to trade RINs. RINs are 

valid for compliance in the calendar year for which they are generated or for 

the following calendar year (within the rollover limit), so a RIN expires if 

unused after 2 years.

With the expanded RFS2 provisions, each obligated party now has four 

RVOs to meet—total renewable fuel, advanced biofuel, biomass-based 

diesel, and cellulosic biofuel—to demonstrate compliance. Previously, the 

 9Separate percentage standards 

were also specifi ed for cellulosic 

biofuel, biomass-based diesel, and 

advanced biofuel. For details, see 

http://www.epa.gov/otaq/fuels/

renewablefuels/420f10056.htm.

 10For example, small refi neries.

The RIN Market Is Key To Implementing 

the Renewable Fuel Standard

Table 2

Renewable volume obligation (RVO) formula and defi nitions

RVOi = (RFStdi x GVi) + Di−1

where

RVOi = The RVO for an obligated party for calendar year i (gallons of renewable fuel).

RFStdi = The renewable fuel standard for calendar year i, determined by EPA (percent).

GVi = The nonrenewable gasoline and diesel volume, which is produced or imported by 

the obligated party in calendar year i (gallons).

Di−1 = Renewable fuel defi cit or carryover from the previous year (gallons).

Source: U.S. Environmental Protection Agency.
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initial RFS established one RVO (total renewable fuel) through 2012 and 

two RVOs (total renewable fuel and cellulosic biofuel) to be met in 2013. 

RFS2 requires that RVOs be calculated based on production or importation 

of both gasoline and diesel fuels. Every physical gallon of renewable fuel 

produced or imported into the United States must be assigned a unique RIN 

for compliance. Equivalence values for every physical gallon of renewable 

fuel represent the number of gallons that can be claimed for compliance 

purposes, based on its energy content compared with ethanol, and adjusted 

for renewable content (see EPA, May 2007 for more information on equivalence values). For example, a gallon of conventional ethanol counts as 1 RIN, 

a gallon of biobutanol counts as 1.3 RINs, a gallon of biodiesel (mono alkyl 

ester) counts as 1.5 RINs, and a gallon of nonester renewable diesel counts as 

1.7 RINs.11

The Core Value of RINs

The actual RIN price includes the core value of RINs, transaction costs, and/

or a speculative component. The core value of a RIN is the gap, if positive, 

between the supply price (Ps

) and the demand price (Pd) for biofuels at any 

given quantity (Thompson et al., 2009b) (fi g. 2). The supply price, corresponding to any point on the supply curve, is the price that allows biofuel 

producers to cover the cost of producing at that output level. Similarly, the 

demand price corresponds to any point on the demand curve that consumers 

(blenders) would be willing to pay for that volume of biofuels without the 

mandates. If the market equilibrium quantity exceeds the mandate, then the 

RIN core value is zero. If the mandate (represented by the vertical RFS2 

line) exceeds the market equilibrium quantity (Qe

), then the RIN core value 

is positive (fi g. 2). Note that the supply price (the price producers receive) 

is equal to the demand price (the price consumers are willing to pay with no 

mandate) plus the core value of the RIN. This calculation assumes that costs 

are covered and mandated levels are produced. In aggregate, the total cost of 

meeting the RFS2 is equal to the mandated quantity times this per-unit cost 

(RIN price). The RIN price, or the gap between supply price and demand 

price, represents the per-unit cost of meeting the mandate. Therefore, a high 

RIN price indicates a high overall cost of meeting the RFS2. 

The RIN Market Ensures that the Mandate Is Met

The RFS2 mandate could be met by each obligated party blending their 

required volume of biofuel and reporting those RINs to the EPA. However, 

a market for RINs has been established to facilitate the trading of the RINs. 

RIN demand comes from obligated parties who fi nd it less expensive to buy 

separated RINs12 than to obtain RINs from purchasing and blending biofuels. 

RIN supply can come from obligated parties who blend more biofuels than 

required, and thus have more RINs than needed for compliance, or from 

nonobligated parties. With an excess supply of RINs, the price of RINs 

becomes negligible.13 If there is a shortage of RINs in the marketplace and 

blenders want to buy more separated RINs than are available, RIN prices will 

increase. RIN prices will rise to bridge the gap between the willingness to 

pay for biofuels and the cost of producing biofuels at the mandated quantity. 

In theory, the RIN market ensures that mandated demand will generate high 

enough biofuel prices to allow biofuel producers to cover their production 

costs up to the RFS2. 

 11The EPA has interpreted the 

biomass-based diesel volume mandate 

as diesel volume rather than as ethanolequivalent volume. Thus, although 1 

gallon of biodiesel (mono alkyl ester) 

counts as 1.5 RINs for the advanced 

biofuel and the total renewable fuel 

standards, it counts as 1 gallon for the 

biomass-based diesel mandate.

 12RINs separated from biofuel after 

the biofuel has been blended. 

 13RIN prices might still be positive, refl ecting transaction costs and/or 

speculative components. 
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What Affects RIN Prices?

As with the overall RFS2 and its submandates, there is also a hierarchy 

for the prices of different types of RINs. For example, advanced biofuel 

RINs will be worth at least as much as conventional ethanol RINs, because 

advanced biofuels count toward both the advanced RFS2 and total RFS2, 

while conventional ethanol only counts toward the total RFS2. 

Tax Credits 

Tax credits make blenders more willing to blend biofuels. The demand curve 

for biofuels shifts upward from D to D’ and the price of RINs drops as represented by the reduction in the “RIN core value” (fi g. 3). Note that if blending 

already exceeded the mandate (D intersected S at a quantity above RFS2), 

RIN prices would be zero. The demand shift to D’ would increase blending 

further but RIN prices would not change, remaining at zero.

In this case, the tax credit would not contribute to meeting the mandate. In 

contrast, eliminating the Volumetric Ethanol Excise Tax Credit (VEETC) 

would make blenders less willing to blend ethanol. In this case, the demand 

curve for ethanol shifts downward from D’ to D, and conventional ethanol 

RIN prices increase. The VEETC is set to expire after December 31, 2011, 

and conventional ethanol RIN prices are expected to rise if this tax credit is 

not renewed unless equilibrium blending remains above the mandate.

Figure 2

Biofuels market with a binding mandate

S=Supply curve.

D=Demand curve.

RFS2=The mandated quantity.

Qe =The equilibrium quantity without the mandate.

Pe =The equilibrium price without the mandate.

Ps =The supply price for biofuels at mandated quantity.

Pd =The demand price for biofuels at mandated quantity.

RIN=Renewable Identification Number.

Source: USDA, Economic Research Service, based on Thompson et al., 2009b.

Pd

Ps

D

RFS2 S

Quantity

Price

Pe

Qe

RIN core value
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The biodiesel blenders’ tax credit expired at the end of 2009; however, at the 

end of 2010, the Tax Relief, Unemployment Insurance Reauthorization, and 

Job Creation Act of 2010 (H.R. 4853) retroactively reinstated and extended 

the biodiesel tax credit through 2011. Extending biodiesel tax credits makes 

blenders more willing to blend biodiesel, thus shifting up the demand curve 

for biodiesel and decreasing the price of biodiesel RINs. As for the VEETC, 

if the biodiesel tax credit is not extended, biodiesel RIN prices would be 

expected to rise.

Crude Oil Prices

Crude oil prices help shape RIN prices, unless blending already exceeds the 

mandate. In most cases, higher crude oil prices lead to an increased willingness to pay for substitute biofuels and shift up the demand curve for biofuels 

(D shifts to D’ as in fi g. 3), thus lowering the price for RINs (RIN core value 

declines in fi g. 3). When crude oil prices drop, consumers’ willingness to pay 

for biofuels decreases. The demand curve for biofuels shifts downward, and 

prices for RINs increase.

Feedstock Prices

Feedstock prices account for a large share of biofuel production costs. A 

surge in feedstock prices will increase biofuel production costs. When feedstocks become more expensive, the supply curve for biofuels shifts upward 

Figure 3

Biofuel market with a demand shift

S=Supply curve.

D=Demand curve.

D’=The shifted demand curve.

RFS2=The mandated quantity.

Ps =The supply price for biofuels at mandated quantity.

Pd =The demand price for biofuels at mandated quantity.

Pd ’ =The new demand price responding to the shifting demand curve.

RIN=Renewable Identification Number.

Source: USDA, Economic Research Service, based on Thompson et al., 2009b. 

Pd

Ps

D

S RFS2

Quantity

Price

Pd’

D’

RIN core value decreases 

as demand for biofuels 

increases from D to D’
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(S to S’ as in fi g. 4) and the prices of RINs increase (larger RIN core value). 

In contrast, lower feedstock prices will reduce production costs, the supply 

curve for biofuels shifts downward, and the prices of RINs decrease. Feedstock production affects the price of the feedstock in the short run. Thus, 

feedstock production also has implications for RIN values. For example, 

when corn production is high, corn prices and production costs of conventional ethanol decrease. Thus, the prices of conventional ethanol RINs 

decrease. The opposite is true when corn production is relatively low.

Speculative Component

Speculators who register with the EPA are allowed to buy and sell RINs. 

For example, if they anticipate a widening gap between market supply and 

demand prices of biofuel at the following year’s mandate, they can buy 

RINs this calendar year to hold and sell the following year. This process 

could potentially reduce the number of RINs available for the current year’s 

compliance and increase RIN prices. 

Historical RIN Prices

The EPA permits RINs from a calendar year to be rolled over for next year’s 

compliance, so extra RINs from 2010 could be used toward meeting the 2011 

RFS2. This rollover provision is subject to a 20 percent cap on the amount 

Figure 4

Biofuel market with a supply shift

S=Supply curve.

S’=Shifted supply curve.

D=Demand curve.

RFS2=The mandated quantity.

Ps =The supply price for biofuels at mandated quantity.

Ps ’ =The new supply price responding to the shifted supply curve.

Pd =The demand price for biofuels at mandated quantity.

RIN=Renewable Identification Number.

Source: USDA, Economic Research Service, based on Thompson et al., 2009b. 

Pd

Ps

D

S

RFS2

Quantity

Price

S’

Ps’

RIN core value 

increases as 

supply decreases 

from S to S’
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of an obligated party’s 2011 RVO that can be met using 2010 RINs (EPA, 

March 2010). RIN prices for both 2010 and 2011 vintages are available 

during 2011. Historical prices indicate that there is a hierarchy of RIN prices 

and that the vintage of the RIN matters. Given the vintage, a biodiesel RIN 

is worth at least the value of a conventional ethanol RIN because a biodiesel 

RIN can meet both noncellulosic advanced and overall mandates. 

For January-August 2011, conventional ethanol RIN prices averaged about 

3 cents (fi g. 5), implying a low probability that the implicit nonadvanced 

mandate is binding for 2011. While the mandates remain important to the 

market, particularly for long-term incentives to develop industry production 

capacity and supporting infrastructures, low RIN prices suggest that other 

factors, such as crude oil prices, have provided incentives to produce more 

than the corresponding mandate. 

During this same period, however, 2011 biodiesel RIN prices averaged 

about $1.24 (fi g. 6). By mid-August 2011, biodiesel RIN prices hit more 

than $1.60. The high biodiesel RIN price implies a more binding biodiesel 

mandate and a signifi cant impact on biodiesel demand. If biodiesel producers 

buy more soybean oil for production, soybean oil prices increase, leading to 

higher demand and prices for competing vegetable oils and fats, as well. 

It is not clear how much of the biodiesel RIN price is attributable to the core 

RIN value, transaction costs, and the speculative component. Nonetheless, a 

high RIN price suggests that a large gap exists between the supply price that 

biodiesel producers need to cover the cost of producing the required amount 

and the demand price that fuel blenders would be willing to pay for the 

Figure 5

Conventional ethanol RIN prices, 2010 and 2011 vintages

RIN=Renewable Identification Number.

Source: Oil Price Information Service (OPIS), Ethanol & Biodiesel Information Service.

Price (dollars per gallon)

0

0.01

0.02

0.03

0.04

Jan.

2011

Feb.

2011

March

2011

April

2011

May

2011

June

2011

July

2011

Aug.

2011

2010 vintage conventional ethanol RIN prices

2011 vintage conventional 

ethanol RIN prices
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quantity without the mandate. In contrast, the positive but low RIN price for 

conventional ethanol may refl ect the speculative component and/or transaction cost.14

Cellulosic Mandate Waivers, Credits, and RIN Prices

For 2010, the EPA reduced the required volume of cellulosic biofuels from 

100 million gallons, as specifi ed by EISA, to 5 million gallons, due to the 

limited production of cellulosic biofuel. In addition, to compensate for low 

cellulosic volume, the EPA made cellulosic biofuel waiver credits available 

to obligated parties for end-of-year compliance at $1.56 per gallon-RIN 

(EPA, March 2010). The number of waiver credits offered could not exceed 

the amount of the cellulosic biofuel standard. For 2011, the EPA reduced the 

required volume of cellulosic biofuels from 250 million gallons, as specifi ed 

by EISA, to 6.6 million gallons. The EPA also made cellulosic biofuel waiver 

credits available to obligated parties for end-of-year compliance at $1.13 per 

credit (EPA, December 2010). These waiver credits cannot be traded or rolled 

forward and can only be used to meet the cellulosic biofuel standard for the 

calendar year offered. Unlike cellulosic biofuel RINs, waiver credits cannot 

be used to meet either the advanced biofuel standard or the total renewable 

fuel standard. Currently, cellulosic biofuel RINs are not available.15

 14The average 2010-vintage conventional ethanol RIN price in 2011 has 

been less than 1 cent, suggesting that 

transaction costs for a conventional 

ethanol RIN may be no higher than 

this amount.

 15For additional information, 

see http://www.epa.gov/otaq/fuels/

renewablefuels/compliancehelp/rfsdata.

htm.

Figure 6

Biodiesel RIN prices, 2010 and 2011 vintages

RIN=Renewable Identification Number.

Source: Oil Price Information Service (OPIS), Ethanol & Biodiesel Information Service.

Price (dollars per gallon)

0

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2010 vintage biodiesel RIN prices

2011 vintage biodiesel RIN prices

Jan.

2011

Feb.

2011

March

2011

April

2011

May

2011

June

2011

July

2011

Aug.

2011
14

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

The development of the conventional ethanol market has depended mainly 

on the interaction of Government policies; the prices of corn, petroleum, and 

coproducts from ethanol production; and technology. Responding to strong 

Government support and high petroleum prices, actual conventional ethanol 

production and consumption exceeded the RFS in 2006, 2007, and 2008, 

and the implicit maximum nonadvanced mandated level in 2009 and 2010 

(fi g. 7). Ethanol’s share (by volume) in the motor gasoline market increased 

signifi cantly from 3.5 percent in 2006 to about 9.5 percent in 2010 (fi g. 8).

While ethanol can be produced from a variety of crops, corn serves as the 

predominant feedstock for U.S. domestic biofuel production. During the last 

3 marketing years, corn used for ethanol production as a share of total corn 

use has increased from 24 percent to 37 percent (fi g. 9). Increased use of 

corn for ethanol production has raised corn prices, which has reduced other 

domestic usage and exports. The decrease in corn for livestock feeding is 

partially offset by the increase in distillers’ grains in livestock rations.16

Greater U.S. demand for corn has contributed to higher corn prices (Trostle, 

2008; OECD/FAO, 2008; Abbott et al., 2008; Westhoff, 2010). Corn prices 

rose from $2.00 per bushel in 2005/06 to an estimated $5.20 per bushel for 

2010/11 (fi g. 10). Higher corn prices have also encouraged producers to 

increase their corn acreage. U.S. cropland planted to corn increased to 93.5 

million acres in 2007, the highest level since 1944. Some of the increase 

in land planted to corn has come from other crops, affecting the markets of 

all fi eld crops. Despite increased corn plantings, corn usage has outpaced 

production growth, reducing carryover stocks (fi g. 11).

 16Distillers’ grains are the primary 

coproduct from dry-mill corn ethanol 

production and can best be used as a 

feed for ruminant animals, such as beef 

cattle and dairy cows. Monogastric 

animals, such as hogs and poultry, are 

more limited in their ability digest the 

distillers’ grains in their rations.

U.S. Conventional Ethanol Market

Figure 7

U.S. ethanol production, consumption, and RFS mandate levels

RFS=Renewable fuel standard.

Source: U.S. Energy Information Administration, Monthly Energy Review, table 10.3, March 2011. 

Billion gallons

Calendar year

14

12

10

8

6

4

2

0

2006 2007 2008 2009 2010

RFS mandate (2006-08); nonadvanced (2009-10)

Ethanol production

Ethanol consumption
15

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

Figure 8

Share of ethanol in U.S. finished gasoline blends

Source: U.S. Energy Information Administration.

Ethanol

9.5%

Gasoline 

90.5%

2010

Ethanol

3%

Gasoline 

97%

2006

Figure 9

U.S. corn use

Source: USDA, Economic Research Service.

Billion bushels

0

2

4

6

8

10

12

14

Marketing year

1980/81 2000/01 82/83 84/85 86/87 88/89 90/91 92/93 94/95 96/97 98/99 02/03 04/05 06/07 08/09 10/11

Feed and residual use

Alcohol for fuel use

Other food, seed, and industrial use

Exports
16

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

Figure 10

Season average farm price of corn and total domestic use of corn, 1980-2010

Note: Latest data may be subject to revision.

Source: USDA, Economic Research Service and National Agricultural Statistics Service.

Billion bushels Dollars per bushel

Marketing year

0.00

1.00

2.00

3.00

4.00

5.00

6.00

0

2

4

6

8

10

12

14

1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010

Total domestic use

Season average prices received

Figure 11

Stocks-to-use ratio for corn

Note: Latest data may be subject to revision.

Source: USDA, Economic Research Service, Feed Grains Database.

Percent

Marketing year

0

10

20

30

40

50

60

70

1975/76 78/79 81/82 84/85 87/88 90/91 93/94 96/97 99/2000 02/03 05/06 08/09
17

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

A variety of potential fuel types can qualify as biomass-based diesel, 

however, biodiesel is the predominant type. In 2008, biodiesel production 

reached 677 million gallons (fi g. 12). Domestic consumption reached its 

highest level at 358 million gallons in 2007. Biodiesel exports surged in 2007 

and 2008, largely to the European Union (EU), as producers sought to benefi t 

from U.S. and EU tax credits. During that time, a $1 per gallon U.S. biodiesel 

tax credit was in place. Any gallon of biodiesel—domestic or imported—that 

was blended with diesel was eligible for this tax credit regardless of the blend 

amount. For the export market, a typical blend is 0.1 percent diesel and 99.9 

percent biodiesel. The resulting blend was then exported to the EU, where it 

was eligible for additional fuel tax credits (Carriquiry and Babcock, 2008). 

Much of the U.S. export surge refl ected imported biodiesel that was blended 

in the United States, and then shipped to its fi nal destination, often in the EU. 

This loophole for foreign biodiesel pass-through was closed in October 2008 

when eligibility for the U.S. tax credit for foreign-produced biodiesel used 

outside the United States was eliminated. Moreover, the EU initiated antidumping laws because U.S. biodiesel accounted for 90 percent of the volume 

of biodiesel imported to the EU market. Since then, both U.S. imports and 

exports of biodiesel have dropped signifi cantly. 

One important characteristic of the U.S. biodiesel industry is its large excess 

capacity. The National Biodiesel Board reported that, as of June 2009, the 

United States supported 173 biodiesel plants with total annual production capacity of 2.69 billion gallons. For 2010, however, actual production 

was only 311 million gallons, implying a capacity utilization rate of about 

U.S. Biodiesel Market

Figure 12

U.S. biodiesel production, trade, and consumption, 2001-10

Source: U.S. Energy Information Administration, Monthly Energy Review, table 10.4, August 2011, 

http://www.eia.doe.gov/totalenergy/data/monthly/index.cfm.

Million gallons

Calendar year

-50

25

100

175

250

325

400

475

550

625

700

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Production Imports

Exports Consumption
18

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

11.6 percent. The low utilization rate of biodiesel capacity was due to the 

low profi tability of producing biodiesel. The spread between biodiesel and 

soybean oil prices is one general indicator of the profi tability of biodiesel 

production (fi g. 13). Economic returns of producing biodiesel from soybean 

oil were low between March 2009 and December 2010, as indicated by the 

small price spread between biodiesel and soybean oil (fi g. 14). In early 2011, 

the profi tability of biodiesel production improved due to strong biodiesel 

prices. The uncertainty of the biodiesel tax credit extension played an important role in the 2010 biodiesel RIN market. The $1-per-gallon tax credit for 

blending biodiesel expired at the end of 2009, but it was not until the end of 

2010 that the tax credit was retroactively reinstated and extended through 

2011. Without biodiesel tax credits, biodiesel RIN prices would be higher. 

The uncertainty regarding the tax credit extension, however, increased the 

risk of biodiesel RIN value declining. 

Although the biodiesel mandate is not defi ned after 2012, the RFS2 of EISA 

requires that at least 1 billion gallons of biodiesel be blended from 2012 

on. Biodiesel can also be used to meet the advanced mandate, so biodiesel 

use could extend beyond its mandated volume to help meet the advanced 

mandate. Thus, the utilization rate of the industry capacity is expected 

to increase. If high biodiesel RIN prices are expected, the profi tability of 

producing biodiesel and its supply will increase because the price biodiesel 

producers receive is equal to the price consumers pay plus the core value 

of biodiesel RINs. Increased production will lead to higher demand for 

biodiesel feedstocks. 

Figure 13

U.S. soybean oil and biodiesel prices, 2008-11

Source: Soybean oil prices calculated based on the contract closing prices from the Chicago Board of Trade; Chicago biodiesel B100 prices 

cacluated based on Oil Price Information Service.

Dollars per gallon

-1.00

0.00

March

2008

June

2008

Oct.

2008

Feb. 

2009

June

2009

Oct.

2009

Feb.

2010

June

2010

Oct.

2010

Feb.

2011

1.00

2.00

3.00

4.00

5.00

6.00

Biodiesel price

Soybean oil price

Spread between biodiesel and soybean oil price
19

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

The feedstocks available for U.S. biodiesel production have become more 

diversifi ed. Prior to 2007, soybean oil was the primary feedstock of biodiesel 

production. Since then, its prominence has decreased as the share of soybean 

oil for biodiesel feedstock dropped to 80 percent in 2007, to 56 percent in 

2008, and to 49.2 percent in 2009 (fi g. 15). Other feedstocks for biodiesel 

production include other vegetable oils, such as canola oil and corn oil, and 

animal fat, such as poultry fat, tallow, white grease, and yellow grease. The 

changing trend in biofuel feedstocks refl ected a policy change that increased 

the tax credit to $1 per gallon for biodiesel made from recycled vegetable oil 

and animal fats. Future market shares will depend on differences in the perunit cost of production between soybean oil and other feedstocks. Increased 

biodiesel production raises demand for vegetable oils and animal fats, 

pushing up their prices. Adjustments occur throughout the vegetable oil and 

animal fats complex as market participants respond to changing price signals. 

In equilibrium, the profi tability of producing biodiesel from soybean oil and 

other feedstocks would be expected to be equal. 

Figure 14

Total U.S. biodiesel production, by feedstock type, 2007-10

Source: Department of Commerce, U.S. Census Bureau, “M311K-Fats and Oils: Production, Consumption, and Stocks,” Current Industrial 

Report, tables 2 and 2a, January 2007–July 2011.

Million pounds

Jan.

2007

May

2007

Sep.

2007

Sep.

2008

Jan.

2008

May

2008

Sep.

2009

Jan.

2009

May

2009

Sep.

2010

Jan.

2010

May

2010

Jan.

2011

May

2011

0

100

200

300

400

500

600

700

Calendar year

Soybean oil

Other feedstocks
20

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

Figure 15

Total U.S. soybean oil use

Source: Historical data based on USDA, Economic Research Service, Oil Crops Yearbook 

2010, table 8; 2009/10 and 2010/11 data based on estimates and forecasts from Oil Crops 

Yearbook 2010, table 3.

Million pounds

Marketing year

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

2005/06 06/07 07/08 08/09 09/10 10/11

Other uses

Methylester (Biodiesel)
21

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

This study examines the market for RINs and the system established by 

the EPA to monitor and enforce provisions of the RFS. As RFS2-mandated 

levels for biofuel use increase, biofuel production will increase along with 

the demand for feedstocks. The total RFS2 for 2011 is 13.95 billion gallons, 

and 12.6 billion gallons make up the unrestricted portion of the mandate for 

which corn ethanol is eligible. Conventional ethanol RIN prices have been 

low in 2011, implying that the implicit nonadvanced ethanol mandate has 

not been binding. Low conventional ethanol RIN prices also suggest that 

factors other than the mandated level have provided economic incentives for 

increased ethanol production. Biodiesel RIN prices have been high in 2011, 

implying a more binding biodiesel mandate with mandate-driven effects on 

markets for soybean oil and other biodiesel feedstocks.

USDA’s 2011 baseline projections suggest that conventional ethanol RIN 

prices could experience some variation in the next 10 years, as the impact 

of the RFS2 on corn markets varies from year to year. Assuming that the 

45-cents-per-gallon tax credit for ethanol blenders and the 54-cents-pergallon tariff on imported fuel ethanol remain in effect, the USDA baseline 

projects that U.S. grain-based ethanol consumption will be above the implicit 

nonadvanced mandated level for 2011 and 2012, but below the implicit 

nonadvanced mandated level for 2013-19, and then above the implicit nonadvanced mandated level again in 2020. When consumption rises above the 

implicit nonadvanced mandate, conventional ethanol RIN prices will be low. 

For other years, the projections suggest that market constraints will limit the 

ability to meet the mandate, thus implying reductions of the RFS2. Alternatively, if the RFS2 were not reduced for those years, conventional ethanol 

RIN prices would likely be higher, further impacting the corn market. 

Alternative projections for ethanol and corn would result if tax credits and 

the import tariff expire at the end of 2011. Tax credits increase a blenders’ 

willingness to pay for ethanol. Without tax credits, blenders have less incentive to use ethanol, making the mandate more binding or subject to reduction. 

Conversely, import tariffs make foreign ethanol more expensive, so removing 

the import tariff would increase ethanol imports. If more sugarcane ethanol 

from Brazil is available for import to meet the noncellulosic and nonbiodiesel 

portion of the advanced mandate, it might become less binding. If the 

advanced mandate is not binding, excess sugarcane ethanol could be used to 

meet the implicit nonadvanced mandate, making it less binding or subject to 

reduction. 

The 2011 USDA baseline assumes that the biodiesel mandate will be held 

constant at 1 billion gallons starting in 2012. The baseline projects that the 

biodiesel mandate will be binding for the next 5-6 years, but that biodiesel 

production and use will exceed the 1 billion gallon mandate later in the 

decade. Use of soybean oil is projected to account for about 50 percent of the 

biodiesel output. To estimate potential biodiesel RIN prices, we calculated a 

simple biodiesel production profi tability indicator—the spread between diesel 

prices and soybean oil prices for the next 10 years—based on USDA baseline 

projections of soybean oil prices and the EIA’s 2010 Annual Energy Outlook 

projections of diesel prices (fi g. 16). The negative price spread initially is 

Outlook and Implications
22

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

consistent with a binding mandate and suggests that biodiesel RIN prices will 

need to be high in the early years. High biodiesel RIN prices will increase 

the profi tability of producing biodiesel, and thus its supply, because the price 

producers receive should be equal to the price consumers are willing to pay 

plus the core value of RINs. The increased production will lead to higher 

demand for biodiesel feedstocks. High biodiesel RIN prices suggest that 

the biodiesel RFS might have a signifi cant impact on its feedstock markets, 

including the soybean oil market. In the later years of the USDA baseline 

(when the price spread in fi g. 16 is positive), projected soybean oil used to 

produce methyl ester rises, suggesting that biodiesel output rises above the 

assumed 1 billion gallon mandate. Here, biodiesel RIN prices are likely to be 

lower since the biodiesel mandate is not binding and market forces (higher 

diesel fuel prices) provide suffi cient economic incentives to meet and exceed 

the mandate. 

Soybean oil price (cents per gallon)

Figure 16

Projected U.S. soybean oil price and diesel fuel price, 2011-20

Source: U.S. Energy Information Administration, 2010 Annual Energy Outlook, table 

12; USDA Agricultural Projections to 2020, February 2011.

Cents per gallon

-200

-100

0

100

200

300

400

500

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Diesel fuel (cents per gallon) 

Spread between diesel price 

and soybean oil price
23

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

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Abbott, Philip C., Christopher Hurt, and Wallace E. Tyner. “What’s Driving 

Food Price?” Farm Foundation Report, July 2008. 

Babcock, B.A. “Renewable Identifi cation Numbers and the Renewable Fuels 

Standard: How They Support Corn and Soybean Prices,” Iowa Ag Review, 

Vol. 15, No. 1, 2009a.

Babcock, B.A. “Intricacies of Meeting the Renewable Fuels Standard,” Iowa 

Ag Review, Vol. 15, No. 2, 2009b.

Carriquiry, M., and B.A. Babcock. “Splashing and Dashing Biodiesel,” Iowa 

Ag Review, Vol. 15, No. 4, 2008.

Congressional Budget Offi ce and Energy Information Administration. 

Monthly Energy Review: May 2010, tables 10.3 and 10.4, 2010, 

http://tonto.eia.doe.gov/FTPROOT/multifuel/mer/00351005.pdf.

Duffi eld, James A., Irene M. Xiarchos, and Steve A. Halbrook. “Ethanol 

Policy: Past, Present, and Future,” South Dakota Law Review, 2008.

Hoffman, L., A. Baker, L. Foreman, and C.E. Young. Feed Grains 

Backgrounder, FDS-07C-01, U.S. Department of Agriculture, Economic 

Research Service, March 2007.

Organisation for Economic Co-operation and Development (OECD) and 

Food and Agriculture Organization (FAO, Paris/Rome). Agricultural 

Outlook: 2008-2017, 2008.

Thompson, W., S. Meyer, and P. Westhoff. Renewable Identifi cation Number 

Markets: Draft Baseline Table, FAPRI-MU Report #07-09, 2009a.

Thompson, W., S. Meyer, and P. Westhoff. “Renewable Identifi cation 

Numbers are the Tracking Instrument and Bellwether of U.S. Biofuel 

Mandates,” EuroChoices, Vol. 8, Issue 3, 2009b.

Thompson, W., S. Meyer, and P. Westhoff. “The New Markets for Renewable 

Identifi cation Numbers,” Applied Economic Perspectives and Policy, 

September 29, 2010. 

Thompson, Wyatt, Seth Meyer, and Travis Green. “The U.S. biodiesel use 

mandate and biodiesel feedstock market,” Biomass and Bioenergy 34: 

pp. 883-89, 2010.

Trostle, Ronald. Global Agricultural Supply and Demand: Factors 

Contributing to the Recent Increase in Food Commodity Prices,

WRS-0801, U.S. Department of Agriculture, Economic Research 

Service, 2010.

U.S. Census Bureau and U.S. Department of Agriculture, Economic Research 

Service. Foreign Trade Statistics, 2010.

U.S. Department of Agriculture, Economic Research Service. Feed Grains 

Database, http://www.ers.usda.gov/Data/Feedgrains/. 

References
24

The Renewable Identifi cation Number System and U.S. Biofuel Mandates / BIO-03

Economic Research Service/USDA

U.S. Department of Commerce, U.S. Census Bureau. “M311K-Fats and Oils: 

Production, Consumption, and Stocks,” Current Industrial Report, tables 

2 and 2a, January 2007-July 2011.

U.S. Environmental Protection Agency. Renewable Fuel Standard, 

www.epa.gov/otaq/fuels/renewablefuels/index.htm.

U.S. Environmental Protection Agency. “Regulation of Fuels and Fuel 

Additives: Renewable Fuel Standard Program; Final Rule,” Federal 

Register, Vol. 72, No. 83, 40 CFR Part 80, May 1, 2007.

U.S. Environmental Protection Agency. “Regulation of Fuels and Fuel 

Additives: Changes to Renewable Fuel Standard Program; Final Rule,” 

Federal Register, Vol. 75, No. 58, 40 C.F.R. Part 80, March 26, 2010.

U.S. Environmental Protection Agency. “Regulation of Fuels and Fuel 

Additives: Modifi cations to Renewable Fuel Standard Program; Final 

Rule and Proposed Rule,” Federal Register, Vol. 75, No. 89, 40 C.F.R. 

Part 80, May 10, 2010.

U.S. Environmental Protection Agency. “Regulation of Fuels and Fuel 

Additives: 2011 Renewable Fuel Standards,” Federal Register, Vol. 75, 

No. 236, 40 C.F.R. Part 80, December 9, 2010.

U.S. Environmental Protection Agency. “Regulation of Fuels and Fuel 

Additives: Modifi cations to Renewable Fuel Standard Program,” Federal 

Register, Vol. 75, No. 244, 40 C.F.R. Part 80, December 21, 2010. 

Westcott, P. Ethanol Expansion in the United States, How Will the 

Agricultural Sector Adjust? FDS-07D-01, U.S. Department of 

Agriculture, Economic Research Service, May 2007, 

www.ers.usda.gov/Publications/FDS/2007/05May/FDS07D01/.

Westcott, P. “Full Throttle: U.S. Ethanol Expansion Faces Challenges Down 

the Road,” Amber Waves (7)3, U.S. Department of Agriculture, Economic 

Research Service, September 2009, www.ers.usda.gov/Amberwaves/

September09/Features/EthanolExpansion.htm. 

Westhoff, Patrick. The Economics of Food: How Feeding and Fueling the 

Planet Affects Food Prices, Pearson Education, Inc. Publishing as FT 

Press: Upper Saddle River, New Jersey, 2010.