Empirical Evidence in Support of Abstinence

A change in the sexual behavior of young people in Zimbabwe probably caused a sharp decline in HIV virus infections in the south African country, according to a study published in the United States.

A reduction in casual sex among experienced men and women, and the delay of others' first sexual experiences, drove a steep fall in the rate of infections of HIV, the virus which causes AIDS, said the study.

Link.

Something so common sensical--the efficacy of abstinence--shouldn't need empirical proof, but for those who need it, they can look to Zimbabwe.