From the World Bank files:

Figure 3 Factors associated with corruption
Note: Each index score is the average for a group of countries. See the Technical Note for details and definitions of the indexes. Higher values of the corruption index mean more corruption, and similarly for the other variables. The top left panel is based on a simple correlation for thirty-nine industrial and developing countries during 1984­93 (for the policy distortion index) and 1996 (for the corruption index). The top right panel is based on a regression using data from fifty-nine industrial and developing countries during 1996. The bottom left panel is based on a regression using data for thirty-five developing countries during 1970­90. The bottom right panel is based on a simple correlation for twenty industrial and developing countries in the late 1980s to the early 1990s; wage data are means. Source: World Bank staff calculations.

Summary