Where the %TSE has experienced a decline this is partly due to high GDP growth rates, and where it has risen in spite of high GDP growth this reflects a stronger intervention. Moreover a low average level of overall support can hide an extremely uneven distribution of support across commodities. This can lead to severe misallocation of resources. These two dimensions of support can be illustrated using the PSE indicators, where the support level is shown by the %PSE and the support composition is characterised by the share of the most production and trade distorting forms in the total PSE. The latter is represented by the sum of PSE transfers based on output (market price support and payments based on output) and payments based on variable input use with no constraints attached.2 Figure 2.13 juxtaposes these two dimensions of the PSE and shows for OECD countries the evolution over time, highlighting two periods, from 1986-88 to 1997-99, and then to the most recent years 2008-10. The %PSE fell in roughly equal steps in both periods: from 37% to 30% in the first period and down to 20% in the second.