Using a sample of over 200 carpools randomized on gender and race, I find that race, in addition to gender, is a significant factor in competitive behavior. Competition-averse preferences, often attributed to females generally, may actually be concentrated among white females. On the aggregate, female drivers do indeed drive slower than male drivers in carpools. Disaggregating the effect by race, however, reveals that white females are responsible for the result, as there are no differences in driving speeds between male drivers and non-white female drivers. These results suggest that competition and gender research may be incomplete without accounting for race.
External Link(s)
Citation
Thompson, Shane. 2018. "Gender, Race, and Competition: Driving Speed with Randomized Passengers." AEA RCT Registry. February 22. https://doi.org/10.1257/rct.2747-1.0.
Driving speed, specifically whether the gender and racial composition of carpools affects driving speeds.
Primary Outcomes (explanation)
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
The slugging commuting process in Washington DC naturally randomizes carpools on gender and race. I measure the effects of various carpool groupings on driving speed.
Experimental Design Details
Randomization Method
Natural randomization. Nature chooses the carpool groupings based on who is next in line.
Randomization Unit
Individual
Was the treatment clustered?
Yes
Sample size: planned number of clusters
Roughly 150-175 individuals
Sample size: planned number of observations
200 carpools
Sample size (or number of clusters) by treatment arms
Roughly 8 gender/race, driver/passenger combinations, or 25 in each grouping.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)