China's campaign against corruption goes back to school this week in an effort to eliminate cheating on college entrance exams.

China says more than seven million high school students will sign honesty pledges before they take their university entrance exams. If they are caught cheating, students' scores will be immediately annulled.

One Communist Party official says it will be an important lesson in credibility, an opportunity to prepare for life in a market economy.

A leading university official says such lessons should have been taught years ago, but were not included in the state-run system.

The annual college exams are intensely competitive and can decide a student's prospects for decades to come. The pressure can be tremendous on students, their families, and teachers. Some families have tried bribing teachers to help their children.

Last week a university official and two private school officials were sent to prison for three years for giving students answers on an English test.

Officials have installed video cameras in some test centers to prevent cheating.

Economists say China could lose as much as 10 percent of its gross domestic product to corruption each year.