Military Career Outcome and Lifespan of 6 Classes of Annapolis and West Point graduates: causation and selection effects

INTRODUCTION: Among military officers, as in many comparable civilian settings, a higher final rank usually is associated with a higher life expectancy or better health conditions. This can be causation: material and immaterial benefits of a higher rank in active service and thereafter may cause life to last longer. Alternatively, there may be selection: those with a robust health may have a greater chance to make it to the top ranks.

METHODS: We investigate graduates of 1949, 1950, 1951 of the US Naval Academy (n=2206) and US Military Academy (n=1719), with 42%, 49%, 49% equally distributed survivors, focusing on men with 20+ years service, when men could retire with benefits. Variation in major intervening variables in this sample is minimal. For Survival analysis we are using the Gompertz-(Gamma)Hazard Model (PH) with Frailty.

RESULTS: Beyond the expected positive association between final rank and life span we find mortality differentials by rank peaking around age 80 then decreasing. This pattern supports selection hypothesis. Modeling unobserved heterogeneity by a frailty variable suggests that leveling off of differential mortality at higher ages is caused by differential loss rate by final rank. Trajectories to different final ranks and different lifespans start drifting apart early. 

CONCLUSIONS: This study suggests an sophisticated approach for analyzing the statistical association between the final military rank and the long-term survival. Further investigation is need for the difference in the cause of death spectrum for commissioned officers.