The Transparency International Corruption Perceptions Index ranks countries in terms of the degree to which corruption is perceived to exist among public officials and politicians. It is a complex index, often called the “survey of surveys”, drawing on corruption-related data from expert and business surveys carried out by various independent and well-known institutions. The CPI reflects views from around the world, including those of experts who are living in the countries evaluated.
The TI CPI focuses on corruption in the public sector, and defines corruption as the abuse of public office for private gain. The surveys used in compiling the CPI ask questions related to the misuse of public power for private benefit, for example bribery of public officials, kickbacks in public procurement, embezzlement of public funds, as well as questions that probe the strength of anti-corruption policies, thereby encompassing both administrative and political corruption.
It is difficult to assess the overall levels of corruption in different countries based on hard empirical data, for example, by comparing the amount of bribes or the number of prosecutions or court cases. For example, in the latter case, comparative data do not reflect actual levels of corruption. Rather, it shows the quality of work done by prosecutors, courts and the media in exposing corruption. Therefore, a useful method of compiling cross-country data is to rely on the experience and perceptions of those who are most directly confronted with corruption in a country.
The complex index scores on a scale from 0 (highly corrupt) to 10 (low levels of corruption, highly clean) using 13 different sources.