Proving Cause and Effect in Traumatic Stress: The Draft Lottery as a Natural Experiment

Compared mortality rates for all draft-eligible vs all draft-exempt men of the Vietnam era. Results established a cause & effect relationship btwn draft eligibility & death by suicide or traffic accidents. The elevated suicide rate appeared to persist until at least 13 yrs after the draft. Results corroborate prev. findings of increased psychological problems among Vietnam vets & suggest that increased psychological problems were caused by military experiences rather than by selection bias.