Role of Selection Bias in Estimates of the Deterrence Effect of Drug Testing: Evidence from the National Logitudinal Survey of Youth

摘要

Substance abuse in the military has serious and costly consequences. The aim of this research is to measure quantitatively the deterrence effect of the military's drug testing and 'zero tolerance' policies. A second purpose is to statistically measure the degree to which selection bias may explain the deterrence effect associated with the military services' drug testing policy. Additionally, this thesis investigates the propensity of service members to substitute legal drugs or alcohol for illicit drugs as a result of drug testing. The results indicate the military's drug prevention policies do have a substantial effect on service members' drug use behavior. The evidence also suggests that self-selection of applicants to the military does not significantly reduce the magnitude of the estimated deterrence effect. However, the results also suggest that there may be an unintended consequence of these policies in the form of military members substituting legal drugs such as alcohol for illegal drugs.