The World Bank Group has published survey data on the level of corruption in various countries and regions where businesses may be required to make unofficial payments or give gifts to "get things done." The survey includes data from more than 125,000 respondents and covers 147 countries and 8 regions. The survey looks at several indicators of corruption, including:

• Percent of firms experiencing at least one bribe payment request;
• Percent of public transactions where a gift or informal payment was requested;
• Percent of firms expected to give gifts in meetings with tax officials;
• Percent of firms expected to give gifts to secure government contracts;
• Value of gift expected to secure a government contract (% of contract value);
• Percent of firms expected to give gifts to get an operating license, import license or construction permit;
• Percent of firms expected to give gifts to get an electrical or water connection;
• Percent of firms expected to give gifts to public officials "to get things done";
• Percent of firms identifying corruption as a major constraint; and
• Percent of firms identifying the courts system as a major constraint.

Regarding tax officials, the most corrupt region overall is East Asia and the Pacific, followed by South Asia, and the Middle East and North Africa.

Click the following link for the survey data.