How reliable is the CPI as a measure of corruption?
If the perceptions consistently reproduce similar assessments it is a good indicator that they are not just referring to cultural or geographical biases but to a real-world phenomenon. The high correlation between the sources we use has actually increased in the past 3 years. The findings suggest that the CPI is a helpful contribution to the understanding of real levels of corruption. The geographical spread of the contributors also contradicts the notion that the CPI is based on the biased perception of Western business people. The following table reports the correlation coefficients of the sources.
