Dropping out of high school, that is, leaving school without graduating, is a central educational issue in almost all industrialized countries, although large differences between educational systems make cross-national or cross-cultural comparisons problematic. Since the beginning of the 1970s, the dropout rates in the industrialized countries have remained relatively stable at between 5 and 10 percent. There is broad international agreement that dropping out increases the risk of subsequent criminal behavior and drug abuse, lower occupational and economic prospects, lower lifetime earnings, and becoming a member of the underclass. Furthermore, dropping out increases the probability of lower levels of mental and physical health. Against the backdrop of all these negative consequences, sociological, educational, and psychological researchers have investigated the reasons for dropping out. The reasons identified can be classified as school-related, family-based, or personal. Researchers agree that the risk of dropping out begins to develop early in a student's life and that intervention programs to prevent dropout should therefore be initiated at an early age. Prevention programs involving counseling sessions on topics such as motivation, relevance of school, academic problems, career goals, and study habits can help to reduce dropout rates.