“Gallantry in Action”: Evidence of Advantageous Selection in a Voluntary Army
利用二战期间美国陆军士兵数据，研究发现志愿兵与征兵在死亡率上无显著差异，但志愿兵获得杰出奖项的比例更高，表明存在有利选择而非不利选择。
A voluntary army’s quality exceeds or falls below a drafted army’s average quality depending on whether selection is advantageous or adverse. Using a collection of data sets that cover the majority of the US Army soldiers during World War II, we test for adverse selection into the army. Rather, we find advantageous selection: volunteers and drafted men showed no significant difference in fatalities, but volunteers earned distinguished awards at a higher rate than drafted men, particularly after the attack on Pearl Harbor. Analyses at the level of units concur with our findings based on enlistment records.