The Corruption Perceptions Index (CPI) is an index developed by Transparency International.
It reflects the perceptions of businesspeole and country experts regarding the level of corruption in the public sector. As the Belgian chapter of Transparency International, we publish the results for Belgium every year.
The results of the CPI 2025 will be published on February 10, 2026.
What does the CPI capture ?
First crime phenomena and integrity breaches violating good governance of the public sector:
- Bribery
- Direction of public funds
- Use of public office for private gain
- Nepotism in the civil service (favoritism for family and friends)
- State capture (systemic corruption in political and administrative decision making)
Secondly the way a state acts and reacts to prevent and to detect these crime phenomena:
- The government’s ability to enforce integrity mechanisms
- The effective prosecution of corrupt officials
- Red tape and excessive bureaucratic burden
- The existence of adequate laws on financial disclosure, conflict of interest prevention and access to information
- Legal protection for whistleblowers, journalists and investigators
How is the CPI calculated ?
1. Selection of source data:
The CPI is calculated by aggregating data from various sources. These sources are selected based on the following criteria: methodological reliability and institutional reputation, conceptual alignment of the data, quantitative granularity, cross country comparability, multi-year data availability. These are sources whose quality is recognized by international experts.
8 sources were used to calculate the Belgium 2025’s CPI:
- Bertelsmann Foundation Sustainable Governance Index
- Economist Intelligence Unit Country Ratings
- Global Insights Country Risk Ratings
- IMD World Competitiveness Yearbook
- PRS International Country Risk Guide
- Varieties of Democracy Project
- World Economic Forum FOS
- World Justice Project
2. Rescaling sources data:
Then, Transparency International standardizes all data sources so they can be comparable and deliver a unique score to a scale of 0 – 100 where 0 equals the highest level of perceived corruption and 100 equals the lowest level of perceived corruption.
3. Aggregating the rescaled data:
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. Reporting a measure for uncertainty:
The CPI is accompanied by a standard error and confidence interval associated with the score (variation in scores of the data sources). In 2012, important changes were made to the methodology to allow for score comparison across time.
Methodology in a nutshell:
- Selection of source data
- Rescaling sources data
- Aggregating the rescaled data
- Reporting a measure for uncertainty.
