Given the development of TI - the global coalition against corruption - there is a higher and higher demand for an in-depth analysis of the causes and consequences of corruption, using both quantitative and qualitative instruments. This task has been assumed by the Policy and Research Department of TI, which coordinates policies and complementary research instruments.
The Global Corruption Barometer (GCB) - an opinion survey which measures the perception of the public on corruption and the experience of the public related to this phenomenon
The Bribe Payers' Index (BPI) - a survey evaluating the premises of corruption at the level of international business transactions, the inclination of companies from highly industrialized countries to use bribe outside their original countries.
The differences between the three indexes concern mainly the respondents to the surveys, as well as the sphere most affected by corruption. Thus, while the CPI evaluates the levels of corruption in the public sector from the perspective of both resident and non-resident experts, the BPI presents the opinions expressed by experts in the business environment regarding the tendencies of companies in the main exporting countries to give bribes on foreign markets - a tendency refered to as the "corruption offer." The GCB presents the public perception of corruption, especially from the perspective of individual experience ("small corruption")
The following pages offer detailed information regarding each of the indexes used to measure corruption in most countries where TI has national representatives.