TITransparency claimsInternational thatcommissioned Prof. Dr J. Graf Lambsdorff of the University of Passau to produce the Corruption Perceptions Index (CPI). The CPI 2005 draws on "16 different polls and surveys from 10 independent institutions… The institutions who provided data for the CPI 2005 are: [[Columbia University]], [[Economist Intelligence Unit]], [[Freedom House]], [[Information International]], [[International Institute for Management Development]], [[Merchant International Group]], [[Political and Economic Risk Consultancy]], [[United Nations Economic Commission for Africa]], [[World Economic Forum]] and [[World Markets Research Centre]]." Early CPIs used public opinion surveys, but now only "experts" are used. TI requires at least three sources to be available in order to rank a country in the CPI. {{ref|2005FAQ}}
TI writes in their FAQ on the CPI that "residents' viewpoints correlate well with those of experts abroad. In the past, the experts surveyed in the CPI sources were often business people from industrialised countries; the viewpoint of less developed countries was underrepresented. This has changed over time, giving increasingly voice to respondents from emerging market economies".{{ref|2005FAQ}}
