Does Military Service Lead to Crime?

(Photo: Ken Mayer)

A new working paper (ungated version) by Jason M. Lindo and Charles F. Stoecker examines the link between military service (in Vietnam) and crime. It has some bad news: “We find that military service increases the probability of incarceration for violent crimes among whites, with point estimates suggesting an impact of 0.27 percentage points.”  The authors also find offsetting impacts on nonviolent crime and hypothesize that “military service may not change an individual’s propensity to commit crime but instead may cause them to commit more-severe crimes involving violence.”

Lindo and Stoecker weren’t able to examine the effects of military service in more recent conflicts, but they express concerns:

[M]ultiple features of today’s military suggest that our results may be relevant today. The military has continued and escalated the use of highly realistic training simulations, a legacy of late-1960s eff orts to desensitize soldiers to engaging with enemy combatants. For example, the military currently uses Iraqi nationals as role-players in training exercises in order to help cadets put a human face and picture on Iraqi society. In addition, the rates of post-traumatic stress disorder for veterans of Iraq and Afghanistan (14 to 25 percent) are quite similar to the rates for those who served in the Vietnam War (18 to 20 percent).


Regarding comparing PTSD rates for recent Iraq/Afghanistan conflicts with Vietnam conflict... one should consider whether the standards for what constitutes PTSD have changed. Also, I would hypothesize: culturally, it may be "more acceptable"/easier to report PTSD today then it was 30 years ago. I find it hard to accept that comparing PTSD rates across a 30 year time span is scientific comparison-- too many compounding variables, I would presume.


Seems like a classic causality trap to me: people join the military because they are COMFORTABLE with violence and see it as a viable problem-solving mechanism. This notion is only reinforced and substantiated in the military, where they also get really good at it....Q.E.D.


This was my first thought, but reading the abstract, they use draft eligibility as their instrument which is actually a clever way to get around reverse causality. So there's no self selection of people with propensities towards violence. If you are drafted, you go.

The problem I see with the paper, having of course, not read anything but the abstract, is that even though everybody got drafted randomly, maybe only the ones with propensities towards violence stay alive throughout the war. They might address this in the paper, but knowing that would require reading it.


A one quarter of one percent increase? That's pretty small. What's the margin of error?


If the background rate of incarceration for violent crime among their non-military compatriots was (say) 0.2%, then an increase of "0.27 percentage points” would mean the vet's rate was 0.47% - more than double. However an increase of "0.27 percent" would normally be interpreted to mean (given 0.2% background) that the vet's rate was 0.20054%.

Note: I pulled the number 0.2% out of the air for the sake of argument. I haven't read the paper, so the author's interpretation of this fine distinction may differ from mine, but I'd be surprised.


P.S. a highly relevant cartoon:


OK, so when people start to shoot others, those who have been to the military are less likely to miss.


Dare I suggest that the data used says nothing about a propensity to commit crimes, but only about the chance of being convicted and incarcerated? Given the unfortunate cultural stereotype of the whacked-out Vietnam vet, it would not surprise me in the least to discover that there's a good deal of profiling, selective prosecution, and stiffer sentences for vets included in there.

Joel Upchurch

Did anyone look at the actual paper?
What they are measuring is DRAFT Eligibility to crimes rates, not actual military service.

While random assignment allows us to cleanly identify the eff ects of draft eligibility, our
data do not allow us to directly estimate the e ect of military service on crime since we
only have data on the population of inmates.

They are just looking at the birth dates of the inmates to estimate their draft lottery number. Frankly this paper seems to be crap. They could have probably gotten better results if they had looked at their astrological signs.


While I am not familiar with the drafting method I wonder if all those draft dodgers (i.e. the rich or those who got into college?) represent a different socieconomic class to those who were not able to avoid the draft? Merely saying I doubt whether the draft is an unbiased sample in itself compared to the general population


And on the other hand, there are those of us with high draft lottery numbers, who still enlisted.


What effect does the universal disdain and vilification of Vietnam vets after the war contribute to this.


What I noticed back in a college report is that veterans leap into hard crimes without ascending through a series of petty crimes first to a statistically significant way. This is well observed in prison populations - no long rap sheet for incarcerated vets. Whether this is from formative years of isolation from the judicial system or a result of military training was just conjecture.


causation issues. I went to school with numerous of people who served. they were given a choice by a local judge: 1) join the military or 2) goto jail.


This "statistic" has been examined before in relation to military members and spousal abuse and the end result wasn't a causation correlation between military training and spousal abuse but a correlation between socioeconomic factors that cause one to join the military and spousal abuse.


The average Vietnam vet is now, what, sixty years old? Has it occurred to anyone that the one quarter of a percent increase in the propensity for violence is simply the result of old age? At that age, does it really matter? Also, I am curious, since the study targets white males, doesn't anyone find this somewhat prejudicial?