The World Bank collects a range of data on corruption, including survey responses from over 100,000 firms worldwide and a set of indicators of governance and institutional quality. Moreover, one of the six dimensions of governance measured by the Worldwide Governance Indicators is Control of Corruption, which is defined as "the extent to which power is exercised for private gain, including both petty and grand forms of corruption, as well as 'capture' of the state by elites and private interests." While the definition itself is fairly precise, the data aggregated into the Worldwide Governance Indicators is based on any available polling: questions range from "is corruption a serious problem?" to measures of public access to information, and not consistent across countries. Despite these weaknesses, the global coverage of these datasets has led to their widespread adoption, most notably by the Millennium Challenge Corporation.

How many firms throughout the world have been surveyed by the World Bank in regards to its corruption study?