Todd and Ralph Stinebrickner find that being assigned a roommate with a video game system reduces first semester GPA by 0.2 points! OLS estimates show that an extra hour/day of studying is only associated with a 0.049 increase in GPA. Exploiting the fact that being assigned a roommate with a video game system reduces time spent studying, they estimate that studying an extra hour a day improves GPAs by 0.356 grade points.
The first result is hard not to accept since roommates are randomly assigned. The last result relies on the usual instrumental variables assumptions. We should be concerned that being assigned a gamer roommate might affect GPAs for reasons other than less time spent studying and the authors do a number of checks to lessen this concern. Also, the sample is only is only about 200 which leads to imprecise estimates. That said, what a neat paper! Major bonus points to the authors for all their shoe-leather. They themselves began the Berea Panel Survey which included the time-diaries.
Paper links: NBER, non-gated version.
(h/t The Borjas Blog)
The first result is hard not to accept since roommates are randomly assigned. The last result relies on the usual instrumental variables assumptions. We should be concerned that being assigned a gamer roommate might affect GPAs for reasons other than less time spent studying and the authors do a number of checks to lessen this concern. Also, the sample is only is only about 200 which leads to imprecise estimates. That said, what a neat paper! Major bonus points to the authors for all their shoe-leather. They themselves began the Berea Panel Survey which included the time-diaries.
Paper links: NBER, non-gated version.
(h/t The Borjas Blog)
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