Corruption Perceptions Index

• 1. Introduction

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  The Corruption Perceptions Index assigns every nation on earth a number between zero and one hundred. Denmark earned an 89 in the 2025 edition, published in February 2026. South Sudan and Somalia each received a 9. That single-digit difference is the chasm between what Transparency International, the German registered association behind the index, describes as the gap between the world's cleanest and most corrupt public sectors.

  The index has run every year since 1995, making it one of the longest-running efforts to hold governments to a visible, comparable standard. More than 180 countries appear in the latest edition. But the score attached to each country is not a measurement of actual corruption. It is a measurement of how corruption is perceived by experts and business executives. That distinction sits at the heart of every argument the index has ever sparked.

• 2. Building the Score

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  Transparency International commissioned Johann Graf Lambsdorff of the University of Passau to develop the original methodology. Early editions relied on public opinion surveys. Since 2012, the process has grown considerably more structured, drawing on 13 surveys and assessments from 12 different institutions.

  Those institutions span the globe. The African Development Bank, based in Ivory Coast, contributes alongside the Bertelsmann Foundation in Germany, the Economist Intelligence Unit in the United Kingdom, and Freedom House in the United States. The World Bank, the World Economic Forum, and the World Justice Project also feed in. A country must be evaluated by at least three of these sources to earn a place in the rankings at all.

  Before any of those source scores can be combined, they go through a standardization process. Researchers convert every data point to a zero-to-100 scale, calculate z-scores using a baseline year, and then rescale the results so the final distribution centers around a mean of roughly 45 with a standard deviation of 20. Scores below zero are set to zero; scores above one hundred are capped. The 2012 methodology revision made this process consistent enough that scores can be compared across years, something the earlier approach did not allow.

  The CPI focuses on specific forms of public sector wrongdoing: bribery, misuse of public funds, abuse of office for personal gain, nepotism in civil service, and state capture. The private sector falls outside its scope entirely, a boundary that has shaped nearly every debate about what the index can and cannot tell us.

• 3. What Corruption Costs

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  Research papers published in 2007 and 2008 found that a one-unit increase in a country's CPI score corresponded to an increase in GDP growth of 1.7%. The same work identified a power-law relationship between higher CPI scores and higher rates of foreign investment.

  A 2019 working paper titled Corruption and Economic Growth: New Empirical Evidence examined data for 175 countries over the period 2012-2018. It found that real per capita GDP decreased by around 17% in the long run when the reversed CPI increased by one standard deviation. The paper also cautioned that many earlier studies used pre-2012 data, when the index was not designed for cross-year comparison, which may have introduced bias into their conclusions.

  A 2020 study of Balkan countries found a positive co-integration relationship between CPI and GDP, and calculated the affecting rate of CPI on GDP as 0.34. The direction of causality, the study concluded, runs from CPI to GDP, not the other way around.

  A 2001 study measuring national environmental performance against 67 variables found that the 2000 Transparency International index correlated with environmental performance at 0.75. A Georgetown University master's thesis from 2013 drew a connection in a different direction: higher income inequality, as measured by the Gini coefficient, was robustly associated with higher perceived corruption.

• 4. Justice, Impunity, and Access

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  Transparency International has reported a correlation between the absence of discrimination and a better CPI score. In countries with high corruption, equal treatment before the law is not guaranteed, and the space for discrimination against specific groups is wider.

  The United Nations Office on Drugs and Crime has noted that justice systems around the world are overburdened with large caseloads, chronically underfunded, and under pressure from outside interference aimed at undermining judicial independence. The World Justice Project's Rule of Law Index showed that in the most recently assessed year, justice systems in most countries exhibited signs of deterioration, including increasing delays and lower levels of accessibility and affordability.

  The 2023 Corruption Perceptions Index identified a positive relationship between corruption and impunity: countries with higher corruption levels are less likely to sanction public officials who fail to follow existing rules. Access to justice itself is affected. A person may rely on personal contacts to change a statutory process rather than receive equal treatment under the law.

• 5. Criticism and Contradiction

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  Political scientist Dan Hough has identified three core problems with the index. First, corruption is too complex to be captured by a single score. The nature of corruption in rural Kansas, Hough argues, differs from that in a city administration like New York's, yet the index treats them identically. Second, measuring perceptions of corruption rather than corruption itself may do no more than reinforce existing stereotypes. Third, the index ignores the private sector entirely, which means that the Libor scandal, the Odebrecht case, and the Volkswagen emissions scandal do not register as corrupt actions in the CPI's accounting.

  Hough nonetheless acknowledged that the index helps keep the fight against corruption on the agendas of policymakers and the global commentariat, and that it is still generally regarded as a decent place to start.

  In a 2013 article in Foreign Policy, Alex Cobham argued that the CPI reflects an elite bias in popular perceptions of corruption. He wrote that the index corrupts perceptions to the extent that it is hard to see a justification for its continuing publication. Cobham also noted that many staff and chapters at Transparency International protest internally over concerns about the index.

  The most pointed dissent came from inside. Johann Graf Lambsdorff, who created the original index, withdrew from work on it in 2009. He stated that he was no longer available for doing the Corruption Perceptions Index.

  Media outlets have added another layer of misuse. They frequently cite raw CPI numbers as a straightforward measure of government performance without explaining what the numbers represent. The local Transparency International chapter in Bangladesh disowned the index results after a methodology change caused the country's scores to increase; press coverage framed it as an improvement in actual corruption rather than a shift in measurement.

• 6. The Limits of a High Score

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  Advanced economies in Northern and Western Europe, North America, and Asia-Pacific have consistently topped the rankings over the long term. Western Europe and the European Union averaged a score of 64 in 2025, against a global average of roughly 42.

  But a high CPI score does not protect a country from being linked to corruption abroad. Transparency International has warned explicitly that a country with a clean domestic score may still be involved in international corruption. Sweden had the third-best CPI score in 2015, while one of its state-owned companies, TeliaSonera, was facing allegations of bribery in Uzbekistan.

  The Netherlands presents a similar case. Despite a high CPI score, it has a poor record of prosecuting companies that bribe foreign officials to win contracts, as illustrated by the Nigerian oil bribery case.

  The report Exporting Corruption 2022, covering 43 of the 44 signatories to the OECD Anti-Bribery Convention plus China, Hong Kong, India, and Singapore, found a significant decline in foreign bribery enforcement. Only two out of 47 countries were in the active enforcement category. Victim compensation in such cases remains rare, and international cooperation, while increasing, still faces significant obstacles.

• 7. Where Things Stand

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  The 2023 Corruption Perceptions Index found that corruption was stagnating at the global level. Of the 180 countries measured, only 28 had improved their scores over the preceding twelve years, while 34 had significantly worsened. No significant change was recorded for 118 countries.

  More than 80 percent of the world's population lived in countries whose CPI score fell below the global average of 43. Among the sharpest declines recorded in 2023 were Venezuela and, more unexpectedly, established democracies: Sweden's score fell by 7 to reach 82, and Great Britain's dropped by 3 to 71. Sri Lanka, Mongolia, Gabon, Guatemala, and Turkey also saw sharp declines.

  Countries recording the most significant improvements over the same twelve-year window included Uzbekistan, Tanzania, Ukraine, Ivory Coast, the Dominican Republic, and Kuwait.

  In the United States, lawyers advising international businesses routinely consult the CPI when assessing risk under the Foreign Corrupt Practices Act. The Minnesota Journal of International Law has criticized that practice, arguing that because the CPI may be subject to perceptual biases, it should not be treated as a reliable measure of actual national corruption risk. That tension between the index's practical utility and its methodological limits remains unresolved, just as it was when the first edition appeared in 1995.