This report is divided into four parts. The first gives a brief description of base area and set-aside provisions in the EU’s direct area payments scheme, and examines the extent to which they are binding. The second part analyses the degree of effective decoupling of the scheme. Particular attention is paid to the impact of base area and set-aside constraints on the degree of decoupling. In the context of total decoupling, the third part looks at the impact of the EU system of direct area payments, in particular base area and set-aside provisions, on the variability of world prices. The final part sets out the conclusions. It endeavours, on the basis of the specific findings reported here, to gain broader insight into the impact of quantitative constraints on the degree of decoupling of support measures to agricultural producers.