The article discusses how import tariffs on farm products don't fully show how much agricultural incentives are distorted in national markets. It also looks at how non-agricultural policies affect agricultural and food markets, especially in developing countries. The researchers suggest that to measure these distortions, we need to consider various policy measures like taxes, subsidies, and restrictions on farm products. They used China as an example to estimate assistance rates to farmers from 1981 to 2005. They also used a model to see how these distortions affect agricultural and non-agricultural markets globally as of 2004.