In 1995, German professor Johann Graf Lambsdorff developed the "Corruption Perceptions Index" at the University of Passau. Corruption can be measured only in a few cases. If something is measured, then it is known. This would contradict the principle that corruption per se is illegal, or at least unethical, and therefore under a certain level of secrecy.
For this reason the corruption index is based on investigations and surveys of nine independent institutions. Both businesspeople and analysts were asked about 182 countries worldwide for their assessment of corruption in the public sector. The index is published annually by Transparency International.
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The evaluation shown here is based on the data for 2025 and lists 92 countries (out of 182 included in the CPI). It is striking that corruption in northern Europe, North America and Australia is very limited. The United States are ranked 23rd at the better end of the scale. This is the worst result for at least 22 years - although we have no records from previous years either. At the bottom of the table is South Sudan.
International ranking of corruption
The top places on the list are obviously occupied by wealthy countries. In particular, European countries, New Zealand, Australia and Canada are mentioned here. At the bottom of the ranking are mostly emerging and developing countries. To clarify this connection, an additional column provides information about the average annual income of the respective country.
This is a shortened overview that only includes the most important countries. Click here for the complete table with all available data from 182 countries.
Good and bad countries
An interpretation of the ranking should not lead to dividing individual countries into benign and malignant. Instead, it rather represents the acceptance of a rule of law and the fear of punishment within the respective country. Transparency International also complains that while many "clean countries" exhibit exemplary behavior in their own countries, they are often associated with corruption in other countries. For example, some countries are in the top ranks, but even partly state-owned companies are involved in bribery scandals abroad. Half of all OECD countries are also accused of similar behavior. Incidentally, with the exception of a few countries in southeastern Europe, the members of the OECD surprisingly coincide with the top quarter of the corruption rankings.
Consequences of corruption in the public sector
Corruption is not only evil because it unfairly discriminates against individual groups of the population. The main problem is in the economic context: If money for personal relationships or favors changes hands, then it is no longer available for necessary expenditures. The example of schools, kindergartens or hospitals becomes particularly clear. Suppliers are usually public institutions such as state or city governments. If the money flows uncontrolled into other channels, the public sector has to suffer. Closely considered, bribe money also remains in the economic cycle, but necessary expenditures can no longer be made with it. As an indirect consequence, economic output falls and inflation rises.
Note on the data basis
The scale used by Transparency International ranges from 0 (high corruption) to 100 (low corruption). Since there is always confusion with this interpretation, we have inverted the scale. Low values here therefore stand for a low perception and high numbers for a high one.
Prosperity and integrity
There is a clear negative correlation between gross domestic product per capita and corruption. Countries with a high income usually achieve quite good values, while countries with a low per capita income often suffer from severe corruption. The statistical correlation is clearly recognizable, but not linear. The gain in integrity is particularly pronounced in the transition from very low to medium income levels, i.e. at around 3,000 to 5,000 dollars per person per year. The effect flattens out as prosperity increases.
A further saturation effect occurs from around 45-50,000 dollars. Up to this per capita income, fundamental institutional deficits are overcome: professional administration, independent courts and functioning control bodies. This alone significantly reduces systemic corruption.
In countries with higher incomes, the problem shifts: overt bribery is then less common than more subtle influence peddling or party financing. However, this no longer hinders state efficiency to such a great extent.
The relationship works in both directions: Rising income strengthens state capacity, improves administration, control and law enforcement and thus also increases transparency. Conversely, low corruption also favors investment and long-term growth. Productivity therefore increases.
This chart shows the distribution of countries according to corruption and GDP. It can be clearly seen that most countries are concentrated in the top left-hand corner, where corruption is high and income is low. The regression line shows a clear downward trend as per capita income increases.
The correlation is not an inevitable dependency. Political institutions, the rule of law and social norms influence the level of corruption in each country independently.
* Dependent territories
The following countries are not sovereign states, but dependent territories or areas of other states:
Hong Kong: special administrative region of China
Taiwan: Semi-presidential republic
Further information on the definition of a country can be found in our article, What is a country?
