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Corruption Perceptions Index 2019:

Frequently Asked Questions

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 by experts and business executives. It is a composite

index, a combination of 13 surveys and assessments of corruption, collected by a

variety of reputable institutions. The CPI is the most widely used indicator of

corruption worldwide.

Which data sources are used for the CPI?

The 2019 CPI draws on 13 data sources from 12 independent institutions

specialising in governance and business climate analysis. The sources of information

used for the CPI 2019 are based on data published in the previous two years. The

CPI includes only sources that provide a score for a set of countries/territories and

that measure expert perceptions of corruption in the public sector. For a full list of the

data sources, the type of respondents and the specific questions asked, please see

the CPI sources description document.

Why do we need the CPI if there are 13 other sources that measure

manifestations of corruption in the public sector?

There are four properties which make the CPI a valuable governance indicator:

1. The CPI has a global geographical coverage.

2. The CPI is more reliable than each source taken separately because it

compensates for eventual errors among sources by taking the average of at

least three different sources and potentially as many as 13.

3. The CPI, with its 0-100 scale, can differentiate between perceived levels of

corruption with more granularity than sources which, for example, have scales

of 1-7 or 1-10 where each country is assigned a full number.

4. Since the underlying CPI sources assess different dimensions and

manifestations of public sector corruption, the CPI manages to reconcile

different aspects of corruption into one indicator.

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. Whilst

researchers from academia, civil society and governments have made advances in

terms of objectively measuring corruption in specific sectors, to date there is no

indicator which measures objective national levels of corruption directly and

exhaustively. The sources and surveys which make up the CPI, ask their

respondents questions which are based on carefully designed and calibrated

questionnaires. (For a list of all sources and the questions that they ask, please see

here.) The CPI contains informed views of relevant stakeholders, which generally

correlate highly with objective indicators, such as citizen experiences with bribery as

captured by the Global Corruption Barometer.

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Which countries/territories are included in the CPI 2019 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 180 countries and territories are

included in the index.

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.

Which manifestations of corruption does the CPI capture?

CPI source data captures the following aspects of corruption, based on the specific

question wording used to collect the data:

 Bribery

 Diversion of public funds

 Prevalence of officials using public office for private gain without facing

consequences

 Ability of governments to contain corruption and enforce effective integrity

mechanisms in the public sector

 Red tape and excessive bureaucratic burden which may increase

opportunities for corruption

 Meritocratic versus nepotistic appointments in the civil service

 Effective criminal prosecution for corrupt officials

 Adequate laws on financial disclosure and conflict of interest prevention for

public officials

 Legal protection for whistleblowers, journalists, investigators when they are

reporting cases of bribery and corruption

 State capture by narrow vested interests

 Access of civil society to information on public affairs

For a full list of the questions used by the CPI sources, please see our source

description document here.

Which manifestations of corruption does the CPI not capture?

CPI source data does not capture the following aspects of corruption:

 Citizens’ perceptions or experience of corruption

 Tax fraud

 Illicit financial flows

 Enablers of corruption (lawyers, accountants, financial advisors etc)

 Money-laundering

 Private sector corruption

 Informal economies and markets

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.

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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 which are not included in the

index.

Can the score of a country in the 2019 CPI 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. Each country score given by the underlying data

sources is rescaled using the global mean and standard deviation from the CPI 2012

as the year of reference. Using this scale we can compare CPI scores from one year

to the next since 2012. Because of the update in the methodology, however, CPI

scores before 2012 are not comparable over time.

For a more detailed description of the change in methodology in 2012, please see

Corruption Perceptions Index – An updated Methodology for 2012.

Where can I find the full tables of results in a time series format?

You can find this on our website here.

I want to reproduce CPI results for my own publication – do I need to ask

permission?

No. Unless otherwise noted, Transparency International’s content is covered by a

Creative Commons Attribution-NoDerivs 4.0 licence. This means you are free to use

our work without contacting us as long as you comply with the terms in the licence.

You comply with the terms of the licence if you credit and link to our material as

follows:

CONTENT TITLE (YEAR) by Transparency International is licensed under CC-BY- ND 4.0

Please link to the TI content under the above mentioned CONTENT TITLE (YEAR).

The attribute “NoDerivs” means that it is not permitted to remix or change the content

under the mentioned licence.

Can I compare results from before 2012?

No, due to a change in our methodology in 2012, results from before that year cannot

be compared. Only CPI results from 2012 onwards can be compared.

Can you compare countries when they are rated by different sources?

Yes. Through our rescaling process, all our sources are brought closer to the global

mean and standard deviation with the baseline of 2012, to allow for cross time

comparison. For a full explanation of our rescaling process, please see our technical

methodology note.

My country has changed CPI score by one or two points? Does that mean

corruption has increased/decreased?

The CPI is a composite indicator, with at least three sources used per country for

calculating the CPI score. For some countries the sources give very similar ratings

while for other countries the sources give a wider range of ratings. We report this

difference using the standard error and upper and lower bounds for the confidence

intervals. Countries which are given similar ratings by the sources will have a smaller

standard error, while countries with a range of source scores will have a larger

standard error. It is unlikely that a one or two point CPI score change would be

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statistically significant. Statistically significant changes are reported in our excel

tables of results. Please see the excel document labelled “Statistically Significant

Changes”.

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 and at the national level through

Transparency International’s network of national chapters based in over 100

countries around the world.

Complementing the CPI, Transparency International has a range of global, regional

and sectoral research products. Full details can be found on our website.

Have there been any independent checks on the validity of the CPI

methodology?

The European Commission Joint Research Centre undertook an independent audit

of the CPI 2017 and its methodology. The same audit was conducted in 2012

following the introduction of a new methodology for the CPI calculation. Both audits

found that the CPI is conceptually and statistically coherent and has a balanced

structure. The full report and recommendations can be found here.

How are statistically significant changes calculated?

Since 2018, Transparency International uses a revised approach to calculate

standard errors and effect sizes, based on advice from the European Commission

Joint Research Centre. Statistically significant movers are calculated using the effect

size, the standard deviation, and the number of sources used for each country.

Changes in CPI scores are considered statistically significant using a 90%

confidence interval. A full explanation, including all formulas, can be found in the

technical methodology note here.

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วัน/เดือน/ปี: 23 มกราคม 2563

หัวข้อ: Corruption Perceptions Index (CPI) 2019

รายละเอียดข้อมูล (โดยสรุปหรือเอกสารแนบ)

Corruption Perceptions Index (CPI) 2019

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