In the mid 90s, Nike ran a commercial extolling the virtues of letting high school girls play sports. “If you let me play, I will . . .” Many studies have backed up Nike’s commercial, showing that those who play sports make more money, receive more schooling, are more self confident, etc. However, these studies may be biased by a selection effect—people who choose to play sports may simply be different than those who do not. For example, motivated people that naturally do better in the workplace may also choose to play sports at a younger age. Since the people who play sports are not a random sample of the population, it is hard to determine whether playing sports benefits the people who play them. There has never been a “natural” experiment where people have been randomly assigned to play sports that would allow us to determine whether playing sports has positive effects.
However, Title IX and the sudden increase in girls playing sports in the 1970s provide a very good substitute for such a natural experiment. Title IX was passed in 1972 and banned gender discrimination in schools. It wasn’t immediately clear how or whether this would apply to sports, but it subsequently became clear that schools would have to make efforts to increase girls’ participation rates. Regardless, once Title IX was passed, schools got the hint immediately and started providing opportunities for girls to play sports. The increase was drastic with girls’ participation rates increasing from almost zero in 1972 to over 25% in 1978, when schools were required to be in compliance.
Professor Betsey Stevenson in a recent paper examined the increase in girls’ sports participation rates in different states to determine the effects of playing sports. Before Title IX, boys’ participation rates varied throughout the United States, anywhere from 25% to near full participation. With the passage of Title IX, schools had to attempt to raise girls’ participation rates to match the boys. This eventually led to girls’ participation rates that were very well correlated with boys’ participation rates. On average, the girls’ participation rate became about half of the boys’ participation rate in each state. Using this, Stevenson could get around the selection effect problem by comparing the changes in educational and vocational outcomes across cohorts for different states and comparing that with the change in girls’ participation as predicted by the pre-Title IX boys’ participation rates for the older cohort, while controlling for other variables such as regional differences and economic status. Since there is no a priori reason why the change in educational and vocation outcomes should be correlated with the change in girls’ sports participation as predicted by the pre-Title IX rates of boys’ participation, the relationship between the two can be interpreted as causal.
The results showed sports do have positive effects. Stevenson estimates that increasing the girls’ sports participation rates by 10 percentage points increased college attendance by 1 to 2 percentage points, increased the chance of full-time employment by over 1 percentage point, and increased the chance that women would work in traditionally male-dominated professions. Since the total increases in girls’ participation rates was 30 percentage points on average, the total effect of Title IX was to increase girls’ college attendance by 3.5 percentage points, increase the full-time employment rate by 4 percentage point, and increase the chance a woman would work in a traditionally male-dominated profession by 1.5 percentage points. These results are far from insignificant as they may account for over 40% of the total increase in women employment statistics over that time period. If you let me play, I will receive a better education and have better job prospects.
However, even this study can’t answer all questions about the effect of sports on the participants. Increased sports participation rates did lead to favorable results, but this could have been because playing sports serves as a signaling function for colleges and future employers. It may have signaled to them that the women who play sports are more driven and therefore will be better students and employees. If this is true, sports may not have any innately positive benefit for participants. Sports just give people a mechanism to signal to future employers that they will be good employees. The effects are still causal in that without the signal of sports, there is not credible alternative to signal these skills to colleges and employers (if there is, then we can rule out signaling as a mechanism to explain Stevenson’s results). Also, it is a good thing that sports serve as a signaling function. Employers and colleges are better able to sort applicants based on their future potential.
Stevenson’s study shows that more women playing sports resulted in positive outcomes. This may be due to increased self-confidence, team skills, and motivation that result from playing sports. But if we were to pass a different policy we may have found even better results by encouraging girls (and boys) to do something else with their time, such as attending more math and science courses. This type of counterfactual is impossible to assess, but reminds us that we can always strive for even better social policy. After all, the sports activities themselves—throwing and catching a ball—don’t translate well into the types of activities most people perform later in life. It’s possible that other activities like math club (mathletics?) would have even greater positive effects. These activities would be a signaling mechanism to future employers and would build life skills. Perhaps if you encourage me to participate in scholastic activities, I will be better off.