Researchers in numerous countries have conducted analyses of alcohol consumption and general population surveys to ascertain the level and consequences of alcohol use. In recent years, investigators also have made attempts to compare drinking rates and other drinking variables across different countries. One reason for researching across national borders, which is of a political nature, is the need for descriptive epidemiology (Room 1988). For example, national governments often want to know how their countries measure up against others in per capita consumption or in other comparative rankings of alcohol use. Another reason for comparative research is the desire to further theoretical knowledge; social scientists often employ comparative designs to develop theories. In the case of alcohol research, comparisons among different countries can help researchers determine how variations in social, cultural, political, environmental, and genetic factors can influence drinking behavior. For example in the case of research on gender differences in alcohol use, international comparisons could help distinguish which differences in men's and women's drinking behaviour can be attributed to biological differences and which to sociocultural factors (Wilsnack et al. 2000).