Due to its nature, the scale of corruption is impossible to quantify with precision. However, there are informed estimates available. Transparency International (TI) regularly publishes several surveys and indices which measure corruption. TI’s Corruption Perceptions Index (CPI) is the best known of their tools. First launched in 1995, it has been widely credited with putting the issue of corruption on the international policy agenda. It measures the perceived levels of public sector corruption in 183 countries and territories around the world. The Global Corruption Barometer is the only world-wide public opinion survey on corruption. The Bribe Payers Index (BPI) ranks the likelihood of companies from 28 leading economies to win business abroad by paying bribes.
The Report on Oil and Gas Companies, which is based on research conducted in 2010 and is an expanded version of a report published in 2008, rates 44 companies on the public availability of information on their anti-corruption programs and how they report their financial results in all the countries where they operate. Finally, a study analyses the transparency of corporate reporting on a range of anti-corruption measures among the 105 largest publicly listed multinational companies. Together these companies are worth more than US$11 trillion and touch the lives of people in countries across the globe, wielding enormous and far reaching power.