Measuring the Immeasurable: What Is Corruption and how to Measure It?

Aneta Pinková

Department of Political Science

Faculty of Social Studies

Masaryk University


Corruption is an elusive term, even if it seems clear enough at first glance. For most of us, corruption equals bribery. This understanding of corruption is common in many linguistic settings and is in fact shared by parts of academia as well. Many definitions of corruption (e.g. Della Porta & Vannucci 2005, Philp 2018) actually include some kind of bribe (favour, illicit payment etc.) or an illegitimate beneficiary of corrupt action (typically the bribe payer). Other approaches to corruption, such as Transparency International’s influential definition of corruption as “an abuse of entrusted power for private gain” (Transparency International 2018) are much broader and essentially, do not exclude corrupt acts involving one person only (the person entrusted with power). While this approach is at odds with the common understanding of corruption, it enables us to include social phenomena such as clientelism, nepotism, misuse of power, graft or state capture. Some researchers consider this approach too broad and (quite rightly) point out that in this broad understanding, the term corruption loses its analytical power. On the other hand, this broad approach reflects the idea that the critical issue with corruption is the misuse of entrusted power (if we stick with Transparency International’s terminology) for private gain. Motivations or the decision-making process leading to it are less important. If a decision-maker decides to award a public contract to a specific company in order to maximize their personal benefit, it does not much matter what form the gain takes (e.g. a bribe or a direct advantage if the decision-maker awards the contract to their own company).

Whether we adopt the narrow or broad approach to corruption, we will face difficulties trying to measure it. Even if we disregard the fact that many believe corruption to be a highly contextual phenomenon depending on time, culture and even context (e.g. CIT) and choose one of the many definitions of corruption available today, there are challenges ahead.

Here are just a few of them:

Should we measure actual levels of corruption or perceived levels of corruption?

Perceptions of corruption are influenced by many other factors apart from respondents’ experience or knowledge of corruption, e.g. overall satisfaction with the government, partisanship, interest in politics or preferred media outlets. On the other hand, actual levels of corruption are impossible to measure and difficult to estimate, because corruption is a clandestine activity and any information we have, such as media coverage or police and judicial statistics, reflect only uncovered cases of this phenomenon.

Should we measure experiences?

Asking about experiences can work well when measuring petty (street-level) corruption. Carefully worded questions treating respondents as potential victims of corruption (typically bribery or racketeering) can help create a realistic picture of how often an “ordinary citizen” pays a bribe or is affected by other forms of bribery. It does not tell us much about the other (often much more severe) forms of corruption e.g., in public procurement, legislation, political parties or about state capture. People actively involved in corruption at these levels are unlikely to share their experience with researchers (or anybody else).

What is the level of corruption?

Is it incidence (the number of corrupt acts), impact (damages resulting from corruption) or illicit gains (e.g., the value of bribes if we subscribe to the narrow understanding of corruption), the share of officials engaged in corruption, the share of official acts which are influenced by corruption, some unspecified “spread” of corruption in a country or the political risk of corruption?

Political, public sector or other?

Many indices, including the well-known Corruption Perception Index (CPI), measure political or public sector corruption, where the perpetrator fulfils some public role or holds public power. For many research purposes this can be problematic because corruption exists in the private sector as well (e.g. business-to-business bribery, where an employee accepts a bribe in exchange for preferential treatment of a particular company).

Should we measure corruption at the national level?

Most corruption indices and indicators assign one number to a whole country. However, we can expect substantial differences in the levels of corruption (whatever they are) between different regions, different sectors of the economy, different levels of public administration etc.


These are just some of the many challenges faced by those who try to measure corruption or use one of the existing measures. On a more positive note, there is no shortage of these tools.



This list includes indicators, indexes, indices, reports, assessment, surveys and other measurement tools devoted directly or indirectly to measuring corruption. The list is very much a work-in-progress however you are welcome to use it. You can also download the Excel file by clicking at the download button.

Included in the list are tools:

  1. a) measuring or evaluating corruption or corruption perception in some of its many forms
  2. b) used as sources for other tools measuring corruption (e.g. composite indices such as Corruption Perception Index or Control of Corruption)
  3. c) used as proxy variables for measuring corruption in published works within academia


If you found a mistake or something missing in the list, please contact me at Thank you!



Della Porta, Donatell – Vannucci, Alberto. 2005. Corruption as a Normative System, CIES – ISCTE (

Philp, Mark. 2018. “The definition of political corruption.” In Heywood, P. M. (Ed.): Routledge Handbook of Political Corruption, pp. 17-30. Abingdon, New York: Routledge.

Transparency International (2018). What Is Corruption? (

Download the above mentioned list

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