Corruption Perceptions Index: In detail


The Corruption Perceptions Index (CPI) ranks countries and territories based on how corrupt their public sector is perceived to be. It is a composite index – a combination of polls – drawing on corruption-related data collected by a variety of reputable institutions. The CPI reflects the views of observers from around the world, including experts living and working in the countries and territories evaluated.

Corruption Perceptions Index 2013: Frequently Asked Questions

 

  1. What is the Corruption Perceptions Index (CPI)?
  2. Why is the CPI based on perceptions?
  3. Which countries/territories are included in the CPI 2013 and why?
  4. What are the data sources for the CPI?
  5. What is the difference between a country/territory’s rank and its score?
  6. Is the country/territory with the lowest score the world's most corrupt nation?
  7. Can the score of a country in the 2013 Corruption Perceptions Index be compared with the previous year?
  8. Which countries have improved/declined on the Corruption Perceptions Index this year?
  9. Does the CPI tell the full story of corruption in a country?

 


1. What is the Corruption Perceptions Index (CPI)?

The CPI scores and ranks countries/territories based on how corrupt a country’s public sector is perceived to be. It is a composite index, a combination of surveys and assessments of corruption, collected by a variety of reputable institutions. The CPI is the most widely used indicator of corruption worldwide.

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2. Why is the CPI based on perceptions?

Corruption generally comprises illegal activities, which are deliberately hidden and only come to light through scandals, investigations or prosecutions. There is no meaningful way to assess absolute levels of corruption in countries or territories on the basis of hard empirical data. Possible attempts to do so, such as by comparing bribes reported, the number of prosecutions brought or studying court cases directly linked to corruption, cannot be taken as definitive indicators of corruption levels. Instead, they show how effective prosecutors, the courts or the media are in investigating and exposing corruption. Capturing perceptions of corruption of those in a position to offer assessments of public sector corruption is the most reliable method of comparing relative corruption levels across countries.

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3. Which countries/territories are included in the CPI 2013 and why?

For a country/territory to be included in the ranking, it must be included in a minimum of three of the CPI’s data sources. If a country is not featured in the ranking, then this is solely because of insufficient survey information and not an indication that corruption does not exist in the country. This year 177 countries and territories are included in the index. In 2012, it was 176. The CPI 2013 now includes South Sudan.

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4. What are the data sources for the CPI?

The 2013 CPI draws on data sources from independent institutions specialising in governance and business climate analysis. The sources of information used for the 2013 CPI are based on data gathered in the past 24 months. The CPI includes only sources that provide a score for a set of countries/territories and that measure perceptions of corruption in the public sector. Transparency International reviews the methodology of each data source in detail to ensure that the sources used meet Transparency International’s quality standards. For a full list of the data sources, the type of respondents and the specific questions they ask, please see the CPI sources description document.

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5. What is the difference between a country/territory’s rank and its score?

A country/territory’s score indicates the perceived level of public sector corruption on a scale of 0-100, where 0 means that a country is perceived as highly corrupt and a 100 means that a country is perceived as very clean. A country's rank indicates its position relative to the other countries/territories included in the index. Ranks can change merely if the number of countries included in the index changes.

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6. Is the country/territory with the lowest score the world's most corrupt nation?

No. The CPI is an indicator of perceptions of public sector corruption, i.e. administrative and political corruption. It is not a verdict on the levels of corruption of entire nations or societies, or of their policies, or the activities of their private sector. Citizens of those countries/territories that score at the lower end of the CPI often show the same concern about and condemnation of corruption as the public in countries that perform strongly.

Further, the country/territory with the lowest score is the one where public sector corruption is perceived to be greatest among those included in the list. The CPI provides no information about countries/territories that are not included in the index.

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7. Can the score of a country in the 2013 Corruption Perceptions Index be compared with the previous year?

Yes. As part of the update to the methodology used to calculate the CPI in 2012 we established the new scale of 0-100. Using this scale we can compare CPI scores from one year to the next. Because of the update in the methodology last year, however, CPI scores before 2012 are not comparable over time.

For a more detailed description of last year’s change in methodology, please see Corruption Perceptions Index – An updated Methodology for 2012.

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8. Which countries have improved/declined on the Corruption Perceptions Index this year?

The biggest Corruption Perceptions Index improvers this year are Myanmar, Brunei, Laos, Senegal, Nepal, Estonia, Greece, Lesotho and Latvia. The biggest decliners are Syria, the Gambia, Guinea-Bissau, Libya, Mali, Spain, Eritrea, Mauritius, Yemen, Australia, Iceland, Slovenia, Guatemala, Madagascar and Congo Republic.

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9. Does the CPI tell the full story of corruption in a country?

No. The CPI is limited in scope, capturing perceptions of the extent of corruption in the public sector, from the perspective of business people and country experts. Complementing this viewpoint and capturing different aspects of corruption, Transparency International produces a range of both qualitative and quantitative research on corruption, both at the global level from its Secretariat and at the national level through Transparency International’s network of National Chapters based in over 90 countries around the world.

Complementing the CPI, Transparency International’s other global research products include:

  • Global Corruption Barometer (GCB): Measuring people’s perceptions and experiences of corruption, the Global Corruption Barometer is a representative survey of more than 114,000 households in 107 countries. The most recent Global Corruption Barometer results (2013) can be found here.
  • Bribe Payers Index (BPI): Measuring the supply side of corruption in international business transaction, the Bribe Payers Index is a ranking of leading exporting countries according to the perceived likelihood of their firms to bribe abroad. It is based on a survey of business executives capturing perceptions of the business practices of foreign firms in their country. The most recent Bribe Payers Index can be found here.
  • Global Corruption Report (GCR): Exploring corruption issues in detail for a specific issue or sector, the Global Corruption Report is a thematic report which draws on a variety of expert research and analysis as well as case studies. The series of Global Corruption Reports, covering issues from the judiciary to education, can be found here.
  • National Integrity System assessments (NIS): A series of in-country studies providing an extensive qualitative assessment of the strengths and weaknesses of the key institutions that enable good governance and prevent corruption in a country. For more information on the National Integrity System reports, please click here.
  • Transparency In Corporate Reporting: The study analyses the extent of transparency in the reporting on a series of anti-corruption measures by the world’s largest companies. For further information, please click here.

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The brochure

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CPI information package

If you'd like to use the Corruption Perceptions Index data, you may download our CPI information package as a ZIP file. It contains an Excel spreadsheet of the full table, notes on the methodology and a description of the index's sources.

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Independent review of CPI methodology

In 2012, the European Commission’s Joint Research Centre conducted an independent assessment of the updated methodology used to compile the Corruption Perceptions Index 2012. The assessment examines the update to the methodology and its treatment of the different data used to compile the index as well as the reliability of the CPI 2012 results.

Download assessment