American high school students devote much less time and energy to their studies than the students of other nations. The cause of the lack of motivation is the lack of rewards for studying hard and for taking rigorous courses. This occurs for four reasons. First, the U.S. economy fails to give academic achievement its due reward in the labor market and rewards instead credentials that signify time spent, rather than competencies acquired. In most other countries credentials are more closely related to competencies obtained, so competencies acquired rather than just time spent are a more important determinant of prestige and income as an adult than they are in the U.S.