Corruption Perceptions Index 2023

METHODOLOGY The CPI aggregates data from several different sources that capture perceptions among businesspeople and country experts of the level of corruption in the public sector. Transparency International takes the following steps to calculate the CPI: 1. Select data sources. Each data source used to construct the CPI must fulfil the following criteria to qualify as a valid source: + Quantifies risks or perceptions of corruption in the public sector + Is based on a reliable and valid methodology + Comes from a reputable organisation + Allows for sufficient variation of scores to distinguish between countries + Ranks a substantial number of countries across more than one region + Considers only the assessments of country experts or businesspeople + Is updated regularly (at least every two years). The CPI is calculated using 13 different data sources from 12 different institutions that have captured perceptions of corruption within the past two years. 2. Standardise data sources to a scale of 0-100. This standardisation is achieved by subtracting the mean of each source in the baseline year from each country score, then dividing by the standard deviation, of that source in the baseline year. This subtraction and division using the baseline year parameters, ensures that the CPI scores are comparable year on year since 2012. After this procedure, the standardised scores are transformed to the CPI scale by multiplying them with the value of the CPI standard deviation in 2012 (20) and adding the mean of the CPI in 2012 (45), so that the dataset fits the CPI’s 0-100 scale. 3. Calculate the average. For a country or territory to be included in the CPI, a minimum of three sources must assess that country. A country’s CPI score is then calculated as the average of all standardised scores available for that country. Scores are rounded to whole numbers. 4. Report the measure of uncertainty. The CPI score is accompanied by a standard error and confidence interval. This captures the variation across the data sources available for a country or territory. TRANSPARENCY INTERNATIONAL 20 Embargoed until 07.01am CET (Berlin) 30 January 2024