The World Corruption Perceptions Index (CPI) is generated by Transparency International and is based on data from various sources that measure perceptions of public sector corruption in different countries.
Transparency International aggregates data from these sources, standardizing the scores on a scale from 0 (highly corrupt) to 100 (very clean). This process involves:
The CPI aggregates and standardizes this data, which is collected within the two years leading up to the publication of the index, to form a score between 0 (highly corrupt) and 100 (very clean). This methodology helps ensure that the CPI reflects a broad consensus of informed perceptions rather than relying on a single source. The final CPI score for each country reflects a composite measure of perceived corruption, providing an annual snapshot that allows for comparisons across countries and over time. In summary, the CPI is based on perceptions of public sector corruption derived from multiple reputable sources, standardized and aggregated to provide a comparative measure of corruption globally.