ATLAS · FIELD GUIDE
The Corruption Perceptions Index: How the World Measures Public-Sector Corruption
Transparency International scores every country from 0 to 100 for how clean its public sector is perceived to be. What does that score actually capture, and what does it deliberately leave out?
Every year, Transparency International scores roughly 180 countries from 0 to 100 on how clean their public sector is perceived to be — 0 for the most corrupt, 100 for the cleanest. The map recolours the world by that score. But the single most important thing about the Corruption Perceptions Index is what it is, and is not, measuring.
It measures perception, not corruption itself
Corruption is hidden by its very nature — no country publishes a true count of every bribe paid or contract rigged. So the index does not try to measure corruption directly. Instead it captures informed perception: how corrupt the public sector is judged to be by country experts and business people, pooled from up to 13 independent surveys and assessments. A country must appear in at least three of those sources to be scored.
This is why it is called a perceptions index, and why the map should be read as Transparency International's assessment rather than a hard measurement.
What it covers, and what it leaves out
The CPI covers the public sector — bribery, diversion of public funds, abuse of office, and the like. It deliberately does not measure private-sector corruption, tax fraud, money laundering, or ordinary citizens' personal experiences of corruption. A country can score well on the CPI and still be a hub for, say, laundering money that originates elsewhere; the index does not capture that.
Reading the map
The cleanest-perceived countries — Denmark, Finland, Singapore, New Zealand — sit in the high 80s and low 90s and glow brightest. The global average has been stuck around 43 for years, and over two-thirds of countries score below 50. Because the method has stayed the same since 2012, scores are comparable over time, but a shift of one or two points in a single year is usually not meaningful.
The map shows the scores exactly as Transparency International publishes them, with the source named on the surface.
Frequently asked questions
What does the Corruption Perceptions Index score mean?
It is a score from 0 to 100, where 0 means a public sector perceived as highly corrupt and 100 means one perceived as very clean. It is published every year by Transparency International, an anti-corruption organisation. A country needs to appear in at least three of the index's underlying data sources to be scored, and roughly 180 countries are included each year. The global average has sat around 43 for years, and more than two-thirds of countries score below 50.
Does the index measure actual corruption?
No, and this is the most important thing to understand about it. The CPI measures perceptions of public-sector corruption — how corrupt the public sector is judged to be by country experts and business people, drawing on up to 13 independent surveys and assessments. There is no way to directly count all the corruption in a country, because corruption is hidden by nature. So the index captures informed perception instead, which is why it is called a perceptions index. It also covers only the public sector, not private-sector fraud, tax evasion, or money laundering.
Which countries score highest and lowest?
The cleanest-perceived countries are consistently in Northern Europe and a few high-income states elsewhere — Denmark, Finland, Singapore and New Zealand are typically near the top, scoring in the high 80s or low 90s. The lowest scores are concentrated in countries affected by conflict and weak institutions. Because the methodology has stayed the same since 2012, scores can be compared over time, though year-to-year changes of one or two points are usually not meaningful.
How should the map be read fairly?
As Transparency International's assessment of perceived corruption, not as a verdict we are issuing. A high score means experts and business surveys perceive a cleaner public sector; a low score means they perceive a more corrupt one. The index is a useful global indicator but a limited one — it reflects perception, covers only the public sector, and cannot capture every dimension of corruption. The map shows the scores exactly as published, with the source named on the surface.
Where does the data come from?
From Transparency International's annual Corruption Perceptions Index, accessed here through Our World in Data's redistribution of it. Transparency International publishes the index under a Creative Commons Attribution-NoDerivatives licence, so the scores are shown unchanged and attributed to Transparency International. The most recent year available is shown, and each value carries its source.
SEE IT ON THE MAP
Everything in this guide is on the live Atlas map.