Measured from 2018-19, girls' participation per 1,000 rose more in law states than in no-law states in every specification, by 39 to 47 participants per 1,000 girls, but the intervals do not all stay above zero. Controlling for each state's lower starting rate gives +39.5 with an interval that just reaches zero (-0.5 to 79.5), and measured from 2021-22, the first post-pandemic survey, the 2022-23 law states only kept pace (-12.6, interval -72.7 to 47.6). Before any law, the future law states were not gaining faster (-16, interval -38 to +6). Boys also rose more in law states (+22), with an interval that includes zero.
Error bars show the 95% confidence interval of each estimate (ciLow to ciHigh).
| ciHigh | ciLevel | ciLow | estimate | label | method | n | spec | standardError | unit |
|---|---|---|---|---|---|---|---|---|---|
| 83.5 | 0.95 | 8.4 | 46 | Main: 2018-19 to 2025-26 | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit | 46 | Main: 2018-19 to 2025-26 | 18.6 | participants per 1,000 girls aged 14-17 |
| 74.7 | 0.95 | 18.6 | 46.7 | Ending 2024-25 | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit | 46 | Ending 2024-25 | 13.9 | participants per 1,000 girls aged 14-17 |
| 78.4 | 0.95 | 3.4 | 40.9 | Without flag football and wrestling | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit | 46 | Without flag football and wrestling | 18.6 | participants per 1,000 girls aged 14-17 |
| 61.1 | 0.95 | 16.8 | 39 | Without questionable NFHS figures | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit | 35 | Without questionable NFHS figures | 10.8 | participants per 1,000 girls aged 14-17 |
| 87.2 | 0.95 | 7.5 | 47.4 | Without court-blocked laws | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit | 43 | Without court-blocked laws | 19.7 | participants per 1,000 girls aged 14-17 |
| 79.5 | 0.95 | -0.5 | 39.5 | Controlling for starting rate (catch-up) | OLS of each state's change on a law-state indicator and its starting rate; HC1 robust standard errors; 95% t interval (see catch-up-check) | 46 | Controlling for starting rate (catch-up) | 19.83 | participants per 1,000 girls aged 14-17 |
| 47.6 | 0.95 | -72.7 | -12.6 | 2022-23 laws, measured from 2021-22 | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit (see did-girls-cohort-b-post-covid-base) | 32 | 2022-23 laws, measured from 2021-22 | 29.4 | participants per 1,000 girls aged 14-17 |
| 6.2 | 0.95 | -38.2 | -16 | Placebo: 2015-16 to 2018-19, before any law | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit | 46 | Placebo: 2015-16 to 2018-19, before any law | 11 | participants per 1,000 girls aged 14-17 |
| 59.1 | 0.95 | -15.3 | 21.9 | Boys (per 1,000 boys) | Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit | 46 | Boys (per 1,000 boys) | 18.5 | participants per 1,000 boys aged 14-17 |