Farm income and commodity support programs have been a part of U.S. farm legislation since the 1930s. Today, these support programs are authorized as part of omnibus U.S. farm legislation—referred to as the farm bill—which has typically been renewed every five or six years. Each successive farm bill usually involves some modification or replacement of existing farm programs. With respect to disciplines governing domestic agricultural support, two WTO agreements are paramount—the Agreement on Agriculture (AoA) and the Agreement on Subsidies and Countervailing Measures (SCM). As a result, designing farm programs that comply with WTO rules can avoid potential trade disputes. A key question that many policymakers ask of virtually every new farm proposal is how it will affect U.S. commitments under the WTO. The AoA contains detailed rules and procedures to guide countries in determining how to classify its programs in terms of which are most likely to distort production and trade; in calculating their annual cost, measured by the Aggregate Measure of Support (AMS) index; and in reporting the total cost to the WTO. Blue box programs are described as production-limiting. The most recent U.S. notification to the WTO of domestic support outlays (made on May 1, 2018) is for the 2015 crop year. The SCM details rules for determining when a subsidy is "prohibited" (as in the case of certain export- and import-substitution subsidies) and when it is "actionable" (as in the case of certain domestic support policies that incentivize overproduction and result in significant market distortion—whether as lower market prices or altered trade patterns). Questions for Evaluating WTO Compliance of Domestic Farm Spending

The United States is currently committed, under the AoA, to spend no more than $19.1 billion per year on amber box trade-distorting support. However, four questions might be asked to determine whether a particular farm measure will cause total U.S. domestic support to be above or below the $19.1 billion annual AMS limit. If it is a potentially trade-distorting "amber box" policy , can support still be excluded from the AMS calculation under the so-called 5% de minimis exemption (explained later in more detail) because total support is no more than 5% of either: the value of total annual production if the support is non-product specific, or the value of annual production of a particular commodity if the support is specific to that commodity? If a program is fully compliant with the AoA rules and limits, does its support result in price or trade distortion in international markets that, in turn, cause adverse effects upon another WTO member? If so, then it may be subject to challenge under SCM rules. Question 1: Can This Measure Be Placed in the Green Box? Through 2015, the most recent year for which the United States has made notifications to the WTO, the United States has never exceeded its $19.1 billion amber box spending limit. An additional consideration for WTO compliance—the SCM rules governing adverse market effects resulting from a domestic farm support program—comes into play when a domestic farm policy effect spills over into international markets. This is particularly relevant for the United States because it is a major producer, consumer, exporter, and/or importer of most major agricultural commodities—but especially of temperate field crops (which are the main beneficiaries of U.S. farm program support). If a particular U.S. farm program is deemed to result in market distortion that adversely affects other WTO members—even if it is compliant with all AoA commitments and agreed-upon spending limits—then that program may be subject to challenge under the WTO dispute settlement procedures.
Omnibus U.S. farm legislation—referred to as the farm bill—has typically been renewed every five or six years. Farm income and commodity price support programs have been a part of U.S. farm bills since the 1930s. Each successive farm bill usually involves some modification or replacement of existing farm programs. A key question likely to be asked of every new farm proposal or program is how it will affect U.S. commitments under the World Trade Organization's (WTO's) Agreement on Agriculture (AoA) and its Agreement on Subsidies and Countervailing Measures (SCM).
The United States is currently committed, under the AoA, to spend no more than $19.1 billion annually on those domestic farm support programs most likely to distort trade—referred to as amber box programs and measured by the Aggregate Measure of Support (AMS). The AoA spells out the rules for countries to determine whether their policies—for any given year—are potentially trade distorting and how to calculate the costs.
The most recent U.S. notification to the WTO of domestic support outlays (made on May 1, 2018) is for the 2015 crop year. To date, the United States has never exceeded its $19.1 billion amber box spending limit. However, this has been achieved in some years (1999, 2000, and 2001) through judicious use of the de minimis exclusion described below.
An additional consideration for WTO compliance—the SCM rules governing adverse market effects resulting from a farm program—comes into play when a domestic farm policy effect spills over into international markets. The SCM details rules for determining when a subsidy is "prohibited" (e.g., certain export- and import-substitution subsidies) and when it is "actionable" (e.g., certain domestic support policies that incentivize overproduction and result in significant market distortion—whether as lower market prices or altered trade patterns). Because the United States is a major producer, consumer, exporter, and/or importer of most major agricultural commodities, the SCM is relevant for most major U.S. agricultural products. As a result, if a particular U.S. farm program is deemed to result in market distortion that adversely affects other WTO members—even if it is within agreed-upon AoA spending limits—then that program may be subject to challenge under the WTO dispute settlement procedures.
Designing farm programs that comply with WTO rules can avoid potential trade disputes. Based on AoA and SCM rules, U.S. domestic agricultural support can be evaluated against five specific successive questions to determine how it is classified under the WTO rules, whether total support is within WTO limits, and whether a specific program fully complies with WTO rules:
Can a program's support outlays be excluded from the AMS total by being placed in the green box of minimally distorting programs? Can a program's support outlays be excluded from the AMS total by being placed in the blue box of production-limiting programs? If amber, will support be less than 5% of production value (either product-specific or non-product-specific) thus qualifying for the de minimis exclusion? Does the total, remaining annual AMS exceed the $19.1 billion amber box limit? Even if a program is found to be fully compliant with the AoA rules and limits, does its support result in price or trade distortion in international markets? If so, then it may be subject to challenge under SCM rules.