Some countries say they want to check the national subsidies that are listed in the green box because they think that some of them could have an impact on production or prices under certain circumstances. Others have said that the green box should not be changed because it is already satisfactory. Some say the green box should be expanded to cover additional types of subsidies. For now, the blue box is a permanent provision of the agreement. Some countries want it removed because payments are only partially decoupled from production, or they propose commitments to reduce the use of these subsidies. Others argue that the blue box is an important tool to support and reform agriculture and achieve certain non-trade objectives, and argue that it should not be limited because it distorts trade less than other types of support (see non-trade concerns). The EU says it is ready to negotiate further cuts to amber-box aid as long as the blue and green box concepts are maintained. A 2009 book by the International Centre for Trade and Sustainable Development (CITSD) showed how green box subsidies distort trade, harm farmers in developing countries and harm the environment. While some green box payments have had little impact on production and trade, others have had a significant impact.  According to the latest official reports from countries to the WTO, the United States paid $76 billion (more than 90% of total spending) to green box payments in 2007, while the European Union reported 48 billion euros ($91 billion) in 2005, or about half of total aid. The EU`s high and growing spending on the green box sector has been decoupled from income assistance, which could have a significant impact on production and trade.  As a result, the trade agreement invites 30 WTO members, including the United States, to commit to reducing their domestic trade-distorting aid that falls into the amber box.
In the absence of these obligations, WTO members are required to maintain their bernstein-box aid between 5 and 10% of their production value. The agreement has been criticized by civil society groups for reducing customs protection for small farmers, an important source of income in developing countries, while allowing rich countries to continue subsidizing agriculture in their own countries. In the run-up to the 1986 GATT Ministerial Conference in Punta del Este, Uruguay, agricultural lobbies in industrialized countries have vehemently opposed agricultural trade-offs. In this context, the idea of excluding “trade-neutral” production and subsidies from WTO commitments was first proposed in 1987 by the United States and soon replicated by the EU.  By guaranteeing continued support to farmers, it has also neutralized the opposition. In exchange for the integration of agriculture into WTO disciplines and the obligation to reduce trade-distorting subsidies in the future, developed countries could maintain subsidies that result in “no more than minimal trade distortion” in order to achieve different public policy objectives.  Third World Network stated: “This has allowed rich countries to maintain or increase their very high subsidies by moving from one kind of subsidy to another… That is why, after the Uruguay Round, subsidies have increased overall in OECD countries, rather than falling, despite the obvious promise to reduce subsidies in the North.
In addition, Martin Khor argued that subsidies to green and blue boxes can also distort trade – because “protection is better camouflaged, but the effect is the same.”  In order to qualify for the green box, the WTO asserts that a subsidy must not distort trade or, at most, lead to minimal distortions.