The findings are based on WEF's Executive Opinion Survey, which interviewed nearly 15,000 business leaders from 141 economies between February and June 2016.
Countries in the corruption index are ranked according survey responses to the following three questions:
1. In your country, how common is illegal diversion of public funds to companies, individuals, or groups?
2. In your country, how do you rate the ethical standards of politicians?
3. In your country, how common is it for firms to make undocumented extra payments or bribes?
Numerical answers are given between one and seven, with one indicating the most corruption and seven indicating the least.
Business Insider looked at the wealthy countries where corruption is most endemic.
To do so, we looked at members of the Organisation for Economic Cooperation and Development, a intergovernmental group of advanced economies, and ranked them according to their position on the corruption index.
Here is the list.