Understanding the Link between Education and Traffic Safety

Monday, June 13, 2016: 3:40 PM
B26 (Stiteler Hall)

Author(s): Darren Grant; Richard Cox

Discussant: Cecilie D Weatherall

The socioeconomic gradient in health is well recognized and, for some conditions, well understood. One that is not well understood is also one of the least recognized: the socioeconomic gradient in traffic fatalities, the leading cause of death for Americans under 40 and one of the top ten overall. Case and Deaton’s recent paper, for example, calculates the transport accident mortality rate of 45-54 year-old, non-Hispanic whites of varying education levels. For individuals with at most a high school degree, the mortality rate is four times that of college graduates.

Such a stark difference is surprising and deserves to be better understood. Therefore, in this paper, we utilize data from the U.S. Census, the Current Population Survey, the U.S. Vital Statistics, and the Fatality Analysis Reporting System (a census of all fatal traffic accidents in the U.S.) to document this socioeconomic gradient in detail and explain its origins.

We begin with panel regressions that relate decades of annual state traffic fatalities to a variety of socioeconomic and demographic variables. These confirm the presence of a socioeconomic gradient, and show that it stems from both education and income, with the former being predominant. The primary educational margin is that of college graduation, rather than that of high school graduation. A one point increase in the percentage of the state’s adult population that has graduated from college corresponds to a 0.3% decrease in the rate of traffic accidents, all else equal. This effect is plausible and, given the sizable number of traffic accidents and the substantial costs they generate, large in absolute magnitude.

Given this finding, we then document the presence of this educational gradient in the U.S., by age, race, and region, utilizing methods analogous to those of Case and Deaton. Across the fifty states and D.C., there is a surprisingly close, essentially linear relationship between education levels and traffic fatality rates.

Finally, we investigate the mechanism behind our panel regression estimates. College graduation and traffic safety could be related in three ways: causally, because education improves driving safety; circumstantially, because safer drivers are more inclined to attend college; or via selection, because the demand for skill draws a disproportionate number of educated, safe drivers to the state. To distinguish between these possibilities, we examine the relation between education and traffic safety among two cohorts that encountered strong, exogenous incentives to attend college: those individuals coming of age during the Vietnam War (who received a draft exemption, see also Buckles et al., 2015), and those coming of age during World War II (who received financial aid via the G.I. Bill). Comparing the estimated effect in these cohorts with that in other cohorts sheds light on the degree to which this relation is causal.

Overall, the results broaden our understanding of traffic safety, of the effects of obtaining higher education, and of the socioeconomic gradient in health.