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What is the Corruption Perceptions Index?

The TI Corruption Perceptions Index (CPI) this year ranks 91 countries in terms of the degree to which corruption is perceived to exist among public officials and politicians. It is a composite index, drawing on 14 different polls and surveys from seven independent institutions carried out among business people and country analysts, including surveys of residents, both local and expatriate.

For the purpose of the TI indices, how is corruption defined?

TI focuses on corruption in the public sector and defines corruption as the abuse of public office for private gain. The surveys used in compiling the CPI tend to ask questions in line with the misuse of public power for private benefits, with a focus, for example, on bribe-taking by public officials in public procurement.

Why is the Corruption Perceptions Index a valuable tool?

Because the CPI is derived from 14 different surveys that garner the perceptions of both residents and expatriates, both business people, academia and risk analysts, the index provides a snapshot of the views of decision-makers, who take key decisions on investment and trade. The CPI builds public awareness of the corruption issue, and it adds to pressure on governments to directly address the issue and the damaged image of their nation that low rankings in the CPI reflect.

What role is played by exporters in international criminal transactions?

In 1999, TI published an additional index that ranked exporting countries according to their propensity to offer bribes. This Bribe Payers Index (BPI) is on the internet . The BPI complements the CPI and underlines the point that corruption in international business transactions involves both those who take and those who give. Looking only at those who take, the CPI provides an incomplete picture. A new BPI is planned in early 2002.

Is it right to conclude that the country with the lowest score is the world's most corrupt country?

No. Firstly, the country with the lowest score is the one perceived to be the most corrupt of those included in the index. The CPI is based on polls, which are snapshots in time and reflect both opinions and experience. Furthermore, there are more than 200 sovereign nations in the world and the CPI 2001 ranks only 91 - TI does not have sufficient reliable data for all countries.

Why is the CPI based on perceptions only?

It is difficult to base comparative statements on the levels of corruption in different countries on hard empirical data, e.g. by comparing the number of prosecutions or court cases. Such cross-country data does not reflect actual levels of corruption; rather it highlights the quality of prosecutors, courts and/or the media in exposing corruption. The only method of compiling comparative data is therefore to build on the experience and perceptions of those who are most directly confronted with the realities of corruption.

Was there any change in the target groups polled for the CPI this year?

There are substantial changes this year, which should serve as a warning not to overstate year-on-year comparisons. This year we used 14 polls from seven institutions compared with 16 polls from eight institutions in 2000. Furthermore, this year we included the new PricewaterhouseCoopers Opacity Index and the new World Business Environment Survey. Each of these surveys sought responses from business people.

What are the criteria in determining which surveys are used?

TI seeks excellent data for the CPI and, to qualify, the data has to be well documented, and it has to be sufficient to permit a judgment on its reliability. TI strives to ensure that the sources used are of the highest quality, that the survey work is performed with complete integrity and that the methodologies used to analyse findings are first class. TI is confident that these criteria apply to the CPI. A more detailed description of the underlying methodology has been written for the 2001 index and is available at our Website or at The methodology used is reviewed by a Steering Committee consisting of leading international experts in the fields of corruption, econometrics and statistics. Members of the Steering Committee make suggestions for improving the CPI, but the management of TI takes the final decisions on the methodology used. Consequently, neither the CPI methodology nor its presentation modality ought to be interpreted as necessarily constituting endorsement by the Steering Committee or its individual members.

Which countries are included in the CPI 2001?

TI requires at least three sources to be available for a country before considering the database sufficiently robust for that country to be ranked in the CPI. Countries for which there might be only one or two data sources available are not included in the CPI. Bangladesh, Dominican Republic, Guatemala, Honduras, Nicaragua, Pakistan, Panama, Trinidad & Tobago and Uruguay have been included because three sources are now available, but were not in 2000.

Were there any countries that were included in the CPI 2000, but not in the CPI 2001?

The countries listed in the accompanying table were included in the 2000 CPI, but could not be included this year because of insufficient topical survey data. The fact that they are not included does not imply in any way that perceptions of corruption relative to these countries have improved or deteriorated over the past year. TI's experience suggests that corruption, particularly for those countries who had scored poorly, remains a major problem, as it does for many others that are not included in the 2000 CPI because of insufficient available data.

CountryScore in 2000
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Is the country score a reliable measure of a country's perceived level of corruption?

In terms of perceptions of corruption, the CPI is a solid measurement tool. The reliability differs, however, between countries. Countries with a low number of sources and large differences in the values provided by the sources (indicated by a large Standard Deviation) convey less reliability as to their score and ranking.

Are old surveys used in the CPI?

The CPI is based on 1999-2001 data. Since fundamental changes in the levels of corruption in a country evolve only slowly, while public perceptions may change more swiftly and be influenced to some extent by short-term events, TI determined to base the CPI on a three-year rolling average. Hence, this year's CPI is based on survey data collected exclusively between 1999 and 2001.

Which sources have contributed to the assessment of each individual country?

A list of sources and surveys from which the CPI is derived follows at the end of the press release. A list of the sources that contributed to the assessment of each country is available on the Internet as an Excel sheet ( or at our Website). This list also provides further information on standard errors and confidence intervals for each country.

Can data from one year be compared with that from a previous year?

Not precisely. The CPI incorporates as many reliable and up-to-date sources as possible. One of the drawbacks to this approach is that year-to-year comparisons of a country's score do not only result from a changing perception of a country's performance but also from a changing sample and methodology. Some sources are not updated and must be dropped as a result, while new, reliable sources are added. With differing respondents and slightly differing methodologies, a change in a country's score cannot be attributed solely to actual changes in a country's performance. Comparisons with the views collected in previous years can therefore be misleading.

Which countries' scores deteriorated most between 2000 and 2001?

Making comparisons from one year to another is problematic. However, to the extent that changes can be traced back to a change in the results from individual sources, trends can be cautiously identified. Noteworthy examples of a downward trend are Malawi, Bolivia, Greece and Norway. The considerable decline in their scores does not result from technical factors - actual changes in perceptions are therefore likely.

Which countries improved most compared with last year?

With the same caveats applied, on the basis of data from sources that have been consistently used for the index, improvements can be observed for Israel, Italy, Colombia and, as already mentioned last year with regard to improvements, Belgium and Japan.