For generations, the prices of farm products have been heavily distorted by government policies in both high-income and developing countries. True, many countries began to reform their agricultural price and trade policies in the 1980s, but a 2009 World Bank book, Distortions to Agricultural Incentives: A Global Perspective, 1955–2007 (edited by Kym Anderson), shows that the extent of intervention is still considerable. In particular, policies still favor agricultural producers in high-income countries relative to those in developing countries – although, as they have become more affluent, some middle-income country governments also are beginning to support their import-competing farmers. This pattern of policies is of concern to the vast majority of the world's poorest households, who depend directly or indirectly on agriculture for their income. And even though low food prices may benefit the urban poor, a 2010 World Bank book, Agricultural Distortions, Inequality and Poverty (edited by Kym Anderson, John Cockburn, and Will Martin), finds that current price-distorting policies still contribute to global inequality and poverty.

If economists are to provide useful advice to national governments on how to reform those policies, a first step is to improve our understanding of why societies have allowed their governments to adopt them in the first place, and why some but not others have subsequently chosen to reverse those welfare-reducing measures. Prerequisites for improving our understanding are better political economy theories, plus better information on the evolving nature and extent of market interventions by governments.