{"sources":[{"id":"nfhs-2015-16","name":"NFHS High School Athletics Participation Survey, 2015-16","url":"https://assets.nfhs.org/umbraco/media/1020203/2015-16_hs_participation_survey.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2015-16","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2016-17","name":"NFHS High School Athletics Participation Survey, 2016-17","url":"https://assets.nfhs.org/umbraco/media/1020204/2016-17_hs_participation_survey.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2016-17","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2017-18","name":"NFHS High School Athletics Participation Survey, 2017-18","url":"https://assets.nfhs.org/umbraco/media/1020205/2017-18_hs_participation_survey.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2017-18","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2018-19","name":"NFHS High School Athletics Participation Survey, 2018-19","url":"https://assets.nfhs.org/umbraco/media/1020412/2018-19_participation_survey.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2018-19, plus girls' wrestling and flag football by state","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2021-22","name":"NFHS High School Athletics Participation Survey, 2021-22","url":"https://assets.nfhs.org/umbraco/media/5989280/2021-22_participation_survey.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2021-22","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2022-23","name":"NFHS High School Athletics Participation Survey, 2022-23","url":"https://assets.nfhs.org/umbraco/media/7212351/2022-23_participation_survey.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2022-23","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2023-24","name":"NFHS High School Athletics Participation Survey, 2023-24","url":"https://assets.nfhs.org/umbraco/media/7213111/2023-24-nfhs-participation-survey-full.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2023-24","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2024-25","name":"NFHS High School Athletics Participation Survey, 2024-25","url":"https://a-us.storyblok.com/f/1022696/x/85a6414d04/2024-25-nfhs-high-school-athletics-participation-survey.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2024-25, plus girls' wrestling and flag football by state","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-2025-26","name":"NFHS High School Athletics Participation Survey, 2025-26","url":"https://a-us.storyblok.com/f/1022696/x/94ea5d9b5f/2025-26_sports_participation_survey_2.pdf","retrievedAt":"2026-10-23","role":"Participation counts by state and sex (Totals by State table) for 2025-26, plus girls' wrestling and flag football by state","licenseName":"NFHS copyright; factual figures used with attribution","licenseUrl":null,"redistribution":"Derived state totals republished with attribution; the PDF itself is linked, not hosted.","reliability":{"publisherKind":"other","interest":"none","note":"The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws."}},{"id":"nfhs-release-2025-26","name":"NFHS news release (August 2026): Led by Girls Flag Football and Girls Wrestling, High School Sports Participation Increases for Fifth Consecutive Year","url":"https://nfhs.org/stories/led-by-girls-flag-football-and-girls-wrestling-high-school-sports-participation-increases-for-fifth-consecutive-year","retrievedAt":"2026-10-23","role":"National 2025-26 totals and the growth of girls' flag football and wrestling","licenseName":"NFHS copyright; quoted with attribution","licenseUrl":null,"redistribution":"Linked, not hosted.","reliability":{"publisherKind":"other","interest":"aligned","note":"NFHS promotes high school sports and reports on its own survey; its framing of growth is promotional, but the figures match the survey tables."}},{"id":"census-v2019","name":"U.S. Census Bureau, Annual Estimates of the Civilian Population by Single Year of Age and Sex for States, 2010-2019 (SC-EST2019-AGESEX-CIV)","url":"https://www2.census.gov/programs-surveys/popest/datasets/2010-2019/state/detail/sc-est2019-agesex-civ.csv","readUrl":"https://www.census.gov/data/datasets/time-series/demo/popest/2010s-state-detail.html","retrievedAt":"2026-10-23","role":"July 1, 2015-2018 civilian population ages 14-17 by sex and state (denominators for 2015-16 to 2018-19)","licenseName":"Public domain (U.S. government work)","licenseUrl":null,"redistribution":"Aggregates republished.","reliability":{"publisherKind":"government","interest":"none","note":"Census Bureau population estimates (Vintage 2019), built from the 2010 Census plus births, deaths and migration."}},{"id":"census-v2025","name":"U.S. Census Bureau, Annual Estimates of the Civilian Population by Single Year of Age and Sex for the United States and States: April 1, 2020 to July 1, 2025 (SC-EST2025-AGESEX-CIV)","url":"https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/state/asrh/sc-est2025-agesex-civ.csv","readUrl":"https://www.census.gov/data/datasets/time-series/demo/popest/2020s-state-detail.html","retrievedAt":"2026-10-23","role":"July 1, 2021-2025 civilian population ages 14-17 by sex and state (denominators for 2021-22 to 2025-26)","licenseName":"Public domain (U.S. government work)","licenseUrl":null,"redistribution":"Aggregates republished.","reliability":{"publisherKind":"government","interest":"none","note":"Census Bureau population estimates (Vintage 2025), built on the 2020 Census base; not strictly continuous with Vintage 2019."}},{"id":"idaho-h500","name":"Idaho Legislature, House Bill 500 (2020), Fairness in Women's Sports Act: bill status","url":"https://legislature.idaho.gov/sessioninfo/2020/legislation/H0500/","retrievedAt":"2026-10-23","role":"Idaho enactment date (signed March 30, 2020; effective July 1, 2020)","licenseName":"Public government record","licenseUrl":null,"redistribution":"Linked.","reliability":{"publisherKind":"government","interest":"none","note":"Official legislative status page; the page notes status updates are unofficial until the journal."}},{"id":"npr-2021-03-27","name":"NPR, Tennessee Becomes 3rd State This Month To Enact Restrictions For Transgender Athletes (March 27, 2021)","url":"https://www.npr.org/2021/03/27/981913132/tennessee-becomes-3rd-state-this-month-to-enact-restrictions-for-transgender-ath","retrievedAt":"2026-10-23","role":"Enactment dates for the Mississippi, Arkansas and Tennessee laws","licenseName":"News report; cited","licenseUrl":null,"redistribution":"Linked.","reliability":{"publisherKind":"news","interest":"none","note":"National news report written at the time of signing."}},{"id":"espn-tracker-2023","name":"ESPN, Transgender athlete laws by state: Legislation, science, more (August 2023)","url":"https://www.espn.com/espn/story/_/id/38209262/transgender-athlete-laws-state-legislation-science","retrievedAt":"2026-10-23","role":"State-by-state bill numbers and enactment dates for laws enacted 2020-2023, and court blocks","licenseName":"News report; cited","licenseUrl":null,"redistribution":"Linked.","reliability":{"publisherKind":"news","interest":"none","note":"State-by-state tracker compiled by ESPN reporters; dated August 2023, so it predates the 2024-2025 laws."}},{"id":"transathlete-tracker","name":"Trans Athlete (transathlete.com), state policy tracker, Take Action page","url":"https://www.transathlete.com/take-action","retrievedAt":"2026-10-23","role":"Wyoming enactment date; Alaska and Virginia listed as policy, not law; count of 29 states","licenseName":"Advocacy page; cited","licenseUrl":null,"redistribution":"Linked.","reliability":{"publisherKind":"advocacy","interest":"none","note":"Maintained by an advocate for transgender athletes' inclusion, which opposes these laws; used only for dates and classifications."}},{"id":"axios-ohio-2024","name":"Axios Columbus, Ohio bill restricting trans health care to take effect in 90 days (January 24, 2024)","url":"https://www.axios.com/local/columbus/2024/01/24/ohio-transgender-bill-senate-veto-override","retrievedAt":"2026-10-23","role":"Ohio HB 68 veto override date","licenseName":"News report; cited","licenseUrl":null,"redistribution":"Linked.","reliability":{"publisherKind":"news","interest":"none","note":"Local news report on the Senate override vote."}},{"id":"nh-bulletin-2024","name":"New Hampshire Bulletin, Sununu signs bans on trans girls in girls' sports, gender affirming surgeries for minors (July 19, 2024)","url":"https://newhampshirebulletin.com/?p=16943","retrievedAt":"2026-10-23","role":"New Hampshire HB 1205 signing date","licenseName":"News report; cited","licenseUrl":null,"redistribution":"Linked.","reliability":{"publisherKind":"news","interest":"none","note":"Nonprofit state news outlet reporting the signing."}},{"id":"nebraska-governor-2025","name":"Office of Governor Jim Pillen, Governor Pillen Signs the Stand With Women Act (June 4, 2025)","url":"https://governor.nebraska.gov/node/9645","retrievedAt":"2026-10-23","role":"Nebraska LB 89 signing date","licenseName":"Public government record","licenseUrl":null,"redistribution":"Linked.","reliability":{"publisherKind":"government","interest":"aligned","note":"Press release from the governor who signed the law."}}],"tables":[{"id":"state-year-participation","title":"Participation and population by state and school year","description":"NFHS boys and girls participants, Census population aged 14-17 by sex, law group, and derived rates.","artifactId":"state-year-participation","unitOfObservation":"State by school year","fields":[{"name":"state","type":"string","description":"State name or District of Columbia","nullable":false,"valueType":"observed","sourceIds":["nfhs-2025-26"]},{"name":"schoolYear","type":"string","description":"School year, such as 2018-19","nullable":false,"valueType":"observed"},{"name":"group","type":"string","description":"law (one of the 27 law states), noLaw (no statewide law or policy), or policy (Alaska, Virginia: state policy, not law)","nullable":false,"valueType":"derived","derivation":"From the state-laws table; policy classification per the Trans Athlete tracker","sourceIds":["espn-tracker-2023","transathlete-tracker"]},{"name":"lawFirstYear","type":"string","description":"First school year counted as covered by the state law","nullable":true,"valueType":"derived","derivation":"First school year starting after enactment (Texas 2021-22, effective January 2022)"},{"name":"girls","type":"integer","units":"participation entries","description":"Girls participants, Totals by State table","nullable":false,"valueType":"observed","sourceIds":["nfhs-2015-16","nfhs-2016-17","nfhs-2017-18","nfhs-2018-19","nfhs-2021-22","nfhs-2022-23","nfhs-2023-24","nfhs-2024-25","nfhs-2025-26"]},{"name":"boys","type":"integer","units":"participation entries","description":"Boys participants, Totals by State table","nullable":false,"valueType":"observed","sourceIds":["nfhs-2015-16","nfhs-2016-17","nfhs-2017-18","nfhs-2018-19","nfhs-2021-22","nfhs-2022-23","nfhs-2023-24","nfhs-2024-25","nfhs-2025-26"]},{"name":"totalReported","type":"integer","units":"participation entries","description":"Total as printed by NFHS (equals boys + girls except North Dakota 2021-22, +90, and Kansas 2024-25, +1)","nullable":false,"valueType":"observed","sourceIds":["nfhs-2021-22","nfhs-2024-25"]},{"name":"girlsPop14to17","type":"integer","units":"persons","description":"Civilian female population aged 14-17 on July 1 of the school year's first calendar year","nullable":false,"valueType":"estimated","sourceIds":["census-v2019","census-v2025"]},{"name":"boysPop14to17","type":"integer","units":"persons","description":"Civilian male population aged 14-17, same basis","nullable":false,"valueType":"estimated","sourceIds":["census-v2019","census-v2025"]},{"name":"girlsPer1000","type":"number","units":"participants per 1,000 girls aged 14-17","description":"1,000 x girls / girlsPop14to17","nullable":false,"valueType":"derived","derivation":"1000*girls/girlsPop14to17, rounded to 0.1"},{"name":"boysPer1000","type":"number","units":"participants per 1,000 boys aged 14-17","description":"1,000 x boys / boysPop14to17","nullable":false,"valueType":"derived","derivation":"1000*boys/boysPop14to17, rounded to 0.1"},{"name":"girlsSharePct","type":"number","units":"percent","description":"Girls as a share of boys + girls participants","nullable":false,"valueType":"derived","derivation":"100*girls/(girls+boys), rounded to 0.01"},{"name":"girlsFlagFootball","type":"integer","units":"participation entries","description":"Girls' flag football participants (2018-19, 2024-25, 2025-26 only; 0 where the state reported none; empty in other years)","nullable":true,"valueType":"observed","sourceIds":["nfhs-2018-19","nfhs-2024-25","nfhs-2025-26"]},{"name":"girlsWrestling","type":"integer","units":"participation entries","description":"Girls' wrestling participants (2018-19, 2024-25, 2025-26 only; empty in other years)","nullable":true,"valueType":"observed","sourceIds":["nfhs-2018-19","nfhs-2024-25","nfhs-2025-26"]},{"name":"girlsExFlagWrestlingPer1000","type":"number","units":"participants per 1,000 girls aged 14-17","description":"Girls per 1,000 excluding flag football and wrestling (empty in other years)","nullable":true,"valueType":"derived","derivation":"1000*(girls-girlsFlagFootball-girlsWrestling)/girlsPop14to17"}]},{"id":"state-laws","title":"State laws limiting girls' school teams to female students","description":"The 27 laws counted, enactment dates and first covered school year.","artifactId":"state-laws","unitOfObservation":"State law","fields":[{"name":"state","type":"string","description":"State","nullable":false,"valueType":"observed","sourceIds":["espn-tracker-2023"]},{"name":"bill","type":"string","description":"Bill number","nullable":false,"valueType":"observed","sourceIds":["espn-tracker-2023","idaho-h500","axios-ohio-2024","nh-bulletin-2024","nebraska-governor-2025"]},{"name":"enacted","type":"date","description":"Date signed, veto overridden, or became law without signature","nullable":false,"valueType":"observed","sourceIds":["espn-tracker-2023","idaho-h500","npr-2021-03-27","transathlete-tracker","axios-ohio-2024","nh-bulletin-2024","nebraska-governor-2025"]},{"name":"firstYear","type":"string","description":"First school year counted as covered","nullable":false,"valueType":"derived","derivation":"First school year beginning after enactment"},{"name":"enjoined","type":"string","description":"yes if the law was blocked in court for all or most students for part of the period","nullable":false,"valueType":"derived","derivation":"From court history in the sources","sourceIds":["espn-tracker-2023"]},{"name":"note","type":"string","description":"Effective dates, court history, scope","nullable":true,"valueType":"observed","sourceIds":["espn-tracker-2023"]}]}],"events":[{"id":"law-idaho","eventType":"stateLawEnacted","date":"2020-03-30","label":"Idaho HB 500","description":"Idaho enacted HB 500, limiting girls' school teams to female students. First school year counted as covered: 2021-22. Effective 2020-07-01; preliminarily enjoined statewide 2020-08-17 (Hecox v. Little); upheld by U.S. Supreme Court 2026-06-30.","sourceIds":["idaho-h500"]},{"id":"law-mississippi","eventType":"stateLawEnacted","date":"2021-03-11","label":"Mississippi SB 2536","description":"Mississippi enacted SB 2536, limiting girls' school teams to female students. First school year counted as covered: 2021-22.","sourceIds":["npr-2021-03-27"]},{"id":"law-arkansas","eventType":"stateLawEnacted","date":"2021-03-25","label":"Arkansas SB 354","description":"Arkansas enacted SB 354, limiting girls' school teams to female students. First school year counted as covered: 2021-22.","sourceIds":["npr-2021-03-27"]},{"id":"law-tennessee","eventType":"stateLawEnacted","date":"2021-03-26","label":"Tennessee SB 228 / HB 3","description":"Tennessee enacted SB 228 / HB 3, limiting girls' school teams to female students. First school year counted as covered: 2021-22.","sourceIds":["npr-2021-03-27"]},{"id":"law-alabama","eventType":"stateLawEnacted","date":"2021-04-23","label":"Alabama HB 391","description":"Alabama enacted HB 391, limiting girls' school teams to female students. First school year counted as covered: 2021-22.","sourceIds":["espn-tracker-2023"]},{"id":"law-west-virginia","eventType":"stateLawEnacted","date":"2021-04-28","label":"West Virginia HB 3293","description":"West Virginia enacted HB 3293, limiting girls' school teams to female students. First school year counted as covered: 2021-22. Blocked as applied to one plaintiff during litigation (West Virginia v. B.P.J.).","sourceIds":["espn-tracker-2023"]},{"id":"law-montana","eventType":"stateLawEnacted","date":"2021-05-07","label":"Montana HB 112","description":"Montana enacted HB 112, limiting girls' school teams to female students. First school year counted as covered: 2021-22.","sourceIds":["espn-tracker-2023"]},{"id":"law-florida","eventType":"stateLawEnacted","date":"2021-06-01","label":"Florida SB 1028","description":"Florida enacted SB 1028, limiting girls' school teams to female students. First school year counted as covered: 2021-22.","sourceIds":["espn-tracker-2023"]},{"id":"law-texas","eventType":"stateLawEnacted","date":"2021-10-25","label":"Texas HB 25","description":"Texas enacted HB 25, limiting girls' school teams to female students. First school year counted as covered: 2021-22. Effective January 2022; the UIL already used birth-certificate sex before the law.","sourceIds":["espn-tracker-2023"]},{"id":"law-south-dakota","eventType":"stateLawEnacted","date":"2022-02-03","label":"South Dakota SB 46","description":"South Dakota enacted SB 46, limiting girls' school teams to female students. First school year counted as covered: 2022-23.","sourceIds":["espn-tracker-2023"]},{"id":"law-iowa","eventType":"stateLawEnacted","date":"2022-03-03","label":"Iowa HF 2416","description":"Iowa enacted HF 2416, limiting girls' school teams to female students. First school year counted as covered: 2022-23.","sourceIds":["espn-tracker-2023"]},{"id":"law-utah","eventType":"stateLawEnacted","date":"2022-03-25","label":"Utah HB 11","description":"Utah enacted HB 11, limiting girls' school teams to female students. First school year counted as covered: 2022-23. Ban preliminarily enjoined by a state court in August 2022; eligibility commission used instead.","sourceIds":["espn-tracker-2023"]},{"id":"law-arizona","eventType":"stateLawEnacted","date":"2022-03-30","label":"Arizona SB 1165","description":"Arizona enacted SB 1165, limiting girls' school teams to female students. First school year counted as covered: 2022-23. Enforcement blocked for plaintiffs by a federal judge July 2023.","sourceIds":["espn-tracker-2023"]},{"id":"law-oklahoma","eventType":"stateLawEnacted","date":"2022-03-30","label":"Oklahoma SB 2","description":"Oklahoma enacted SB 2, limiting girls' school teams to female students. First school year counted as covered: 2022-23.","sourceIds":["espn-tracker-2023"]},{"id":"law-kentucky","eventType":"stateLawEnacted","date":"2022-04-13","label":"Kentucky SB 83","description":"Kentucky enacted SB 83, limiting girls' school teams to female students. First school year counted as covered: 2022-23.","sourceIds":["espn-tracker-2023"]},{"id":"law-georgia","eventType":"stateLawEnacted","date":"2022-04-28","label":"Georgia HB 1084 (GHSA rule)","description":"Georgia enacted HB 1084 (GHSA rule), limiting girls' school teams to female students. First school year counted as covered: 2022-23. GHSA rule adopted May 2022 under HB 1084.","sourceIds":["espn-tracker-2023"]},{"id":"law-south-carolina","eventType":"stateLawEnacted","date":"2022-05-16","label":"South Carolina H.4608","description":"South Carolina enacted H.4608, limiting girls' school teams to female students. First school year counted as covered: 2022-23.","sourceIds":["espn-tracker-2023"]},{"id":"law-indiana","eventType":"stateLawEnacted","date":"2022-05-24","label":"Indiana HEA 1041","description":"Indiana enacted HEA 1041, limiting girls' school teams to female students. First school year counted as covered: 2022-23.","sourceIds":["espn-tracker-2023"]},{"id":"law-louisiana","eventType":"stateLawEnacted","date":"2022-06-06","label":"Louisiana SB 44","description":"Louisiana enacted SB 44, limiting girls' school teams to female students. First school year counted as covered: 2022-23.","sourceIds":["espn-tracker-2023"]},{"id":"law-wyoming","eventType":"stateLawEnacted","date":"2023-03-17","label":"Wyoming SF 133","description":"Wyoming enacted SF 133, limiting girls' school teams to female students. First school year counted as covered: 2023-24.","sourceIds":["transathlete-tracker"]},{"id":"law-kansas","eventType":"stateLawEnacted","date":"2023-04-05","label":"Kansas HB 2238","description":"Kansas enacted HB 2238, limiting girls' school teams to female students. First school year counted as covered: 2023-24.","sourceIds":["espn-tracker-2023"]},{"id":"law-north-dakota","eventType":"stateLawEnacted","date":"2023-04-11","label":"North Dakota HB 1489 / HB 1249","description":"North Dakota enacted HB 1489 / HB 1249, limiting girls' school teams to female students. First school year counted as covered: 2023-24.","sourceIds":["espn-tracker-2023"]},{"id":"law-missouri","eventType":"stateLawEnacted","date":"2023-06-07","label":"Missouri SB 39","description":"Missouri enacted SB 39, limiting girls' school teams to female students. First school year counted as covered: 2023-24.","sourceIds":["espn-tracker-2023"]},{"id":"law-north-carolina","eventType":"stateLawEnacted","date":"2023-08-16","label":"North Carolina HB 574","description":"North Carolina enacted HB 574, limiting girls' school teams to female students. First school year counted as covered: 2023-24.","sourceIds":["espn-tracker-2023"]},{"id":"law-ohio","eventType":"stateLawEnacted","date":"2024-01-24","label":"Ohio HB 68","description":"Ohio enacted HB 68, limiting girls' school teams to female students. First school year counted as covered: 2024-25. Veto overridden 2024-01-24; effective 90 days later.","sourceIds":["axios-ohio-2024"]},{"id":"law-new-hampshire","eventType":"stateLawEnacted","date":"2024-07-19","label":"New Hampshire HB 1205","description":"New Hampshire enacted HB 1205, limiting girls' school teams to female students. First school year counted as covered: 2024-25. Grades 5-12.","sourceIds":["nh-bulletin-2024"]},{"id":"law-nebraska","eventType":"stateLawEnacted","date":"2025-06-04","label":"Nebraska LB 89","description":"Nebraska enacted LB 89, limiting girls' school teams to female students. First school year counted as covered: 2025-26. Effective 2025-09-03.","sourceIds":["nebraska-governor-2025"]},{"id":"covid-survey-gap","eventType":"dataGap","startDate":"2019-07-01","endDate":"2021-06-30","label":"No NFHS survey for 2019-20 or 2020-21","description":"NFHS lists 2019-20 and 2020-21 as \"Data unavailable due to COVID-19 pandemic.\"","sourceIds":["nfhs-2025-26"]}],"analyses":[{"id":"rate-by-group-year","title":"Participation per 1,000 high-school-age residents, law states vs. no-law states","question":"How did girls' and boys' high school sports participation per 1,000 residents aged 14-17 change in states that passed laws limiting girls' teams to female students, compared with states that did not?","operation":"Sum NFHS participants by sex across each group of states, divide by the group's Census civilian population aged 14-17 of that sex, times 1,000.","parameters":{"lawGroup":"24 states whose law first applied in 2021-22, 2022-23 or 2023-24","noLawGroup":"22 jurisdictions with no statewide law or policy (incl. DC)","excluded":"Ohio, New Hampshire, Nebraska (laws from 2024-25 on); Alaska and Virginia (state policy, not law)"},"scope":"School years 2015-16 to 2025-26; 2019-20 and 2020-21 have no survey and are null.","resultShape":"timeSeries","structuredResult":[{"schoolYear":"2015-16","series":"Girls, law states","rate":366},{"schoolYear":"2015-16","series":"Boys, law states","rate":513.5},{"schoolYear":"2015-16","series":"Girls, no-law states","rate":434.6},{"schoolYear":"2015-16","series":"Boys, no-law states","rate":534.5},{"schoolYear":"2016-17","series":"Girls, law states","rate":377.9},{"schoolYear":"2016-17","series":"Boys, law states","rate":515},{"schoolYear":"2016-17","series":"Girls, no-law states","rate":441.8},{"schoolYear":"2016-17","series":"Boys, no-law states","rate":539.7},{"schoolYear":"2017-18","series":"Girls, law states","rate":373.5},{"schoolYear":"2017-18","series":"Boys, law states","rate":512.9},{"schoolYear":"2017-18","series":"Girls, no-law states","rate":449.2},{"schoolYear":"2017-18","series":"Boys, no-law states","rate":542.6},{"schoolYear":"2018-19","series":"Girls, law states","rate":370.1},{"schoolYear":"2018-19","series":"Boys, law states","rate":512.2},{"schoolYear":"2018-19","series":"Girls, no-law states","rate":453.4},{"schoolYear":"2018-19","series":"Boys, no-law states","rate":543.3},{"schoolYear":"2019-20","series":"Girls, law states","rate":null},{"schoolYear":"2019-20","series":"Boys, law states","rate":null},{"schoolYear":"2019-20","series":"Girls, no-law states","rate":null},{"schoolYear":"2019-20","series":"Boys, no-law states","rate":null},{"schoolYear":"2020-21","series":"Girls, law states","rate":null},{"schoolYear":"2020-21","series":"Boys, law states","rate":null},{"schoolYear":"2020-21","series":"Girls, no-law states","rate":null},{"schoolYear":"2020-21","series":"Boys, no-law states","rate":null},{"schoolYear":"2021-22","series":"Girls, law states","rate":353.4},{"schoolYear":"2021-22","series":"Boys, law states","rate":479.4},{"schoolYear":"2021-22","series":"Girls, no-law states","rate":400.2},{"schoolYear":"2021-22","series":"Boys, no-law states","rate":486.9},{"schoolYear":"2022-23","series":"Girls, law states","rate":353.4},{"schoolYear":"2022-23","series":"Boys, law states","rate":490.3},{"schoolYear":"2022-23","series":"Girls, no-law states","rate":418.2},{"schoolYear":"2022-23","series":"Boys, no-law states","rate":512.7},{"schoolYear":"2023-24","series":"Girls, law states","rate":366.6},{"schoolYear":"2023-24","series":"Boys, law states","rate":495},{"schoolYear":"2023-24","series":"Girls, no-law states","rate":427.9},{"schoolYear":"2023-24","series":"Boys, no-law states","rate":529.5},{"schoolYear":"2024-25","series":"Girls, law states","rate":379.1},{"schoolYear":"2024-25","series":"Boys, law states","rate":506.5},{"schoolYear":"2024-25","series":"Girls, no-law states","rate":439.1},{"schoolYear":"2024-25","series":"Boys, no-law states","rate":539.7},{"schoolYear":"2025-26","series":"Girls, law states","rate":401.8},{"schoolYear":"2025-26","series":"Boys, law states","rate":527.7},{"schoolYear":"2025-26","series":"Girls, no-law states","rate":452.7},{"schoolYear":"2025-26","series":"Boys, no-law states","rate":542.8}],"displayResult":"Girls per 1,000: law states 370.1 (2018-19) to 401.8 (2025-26); no-law states 453.4 to 452.7. Boys per 1,000: law states 512.2 to 527.7; no-law states 543.3 to 542.8.","methodologicalNotes":["Pooled (population-weighted) rates. School year Y-(Y+1) uses the July 1, Y population estimate.","2015-16 to 2018-19 use Census Vintage 2019 and later years Vintage 2025; the two vintages are not strictly continuous."],"limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-girls-main","title":"Difference-in-differences: girls per 1,000, 2018-19 to 2025-26","question":"Did girls' participation per 1,000 girls aged 14-17 change differently in the 24 law states than in the 22 no-law states between the last pre-pandemic survey (2018-19) and the latest (2025-26)?","operation":"For each state, rate in 2025-26 minus rate in 2018-19; mean in law states minus mean in no-law states.","scope":"24 law states vs 22 no-law jurisdictions; states unweighted.","resultShape":"estimate","structuredResult":[{"label":"Law states minus no-law states, change in girls per 1,000, 2018-19 to 2025-26","estimate":46,"standardError":18.6,"ciLow":8.4,"ciHigh":83.5,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"Law states +45.2 per 1,000, no-law states -0.8; difference +46.0 (95% CI 8.4 to 83.5).","methodologicalNotes":["Every law in the law group was first in force between the two survey years.","The Welch interval treats each state as one observation; it does not model reporting error within states."],"limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z","robustnessChecks":[{"analysisId":"placebo-girls-pre-period","checkType":"placebo","summary":"Before any law (2015-16 to 2018-19), the future law states grew 16 per 1,000 less than the others (95% CI -38 to +6): no head start, so the later gap is not a continuing pre-trend."},{"analysisId":"did-girls-2024-25","checkType":"sensitivity","summary":"Ending in 2024-25 instead gives +46.7 (18.6 to 74.7), so the result does not depend on the 2025-26 survey."},{"analysisId":"did-girls-excl-flag-wrestling","checkType":"sensitivity","summary":"Leaving out girls' flag football and wrestling, the fastest-growing sports, gives +40.9 (3.4 to 78.4)."},{"analysisId":"did-girls-excl-flagged","checkType":"sensitivity","summary":"Dropping 13 jurisdictions whose NFHS totals repeat a prior year or jump more than 25% in a year gives +39.0 (16.8 to 61.1)."},{"analysisId":"did-girls-excl-enjoined","checkType":"sensitivity","summary":"Dropping Idaho, Utah and Arizona, whose laws were blocked in court for some or all students, gives +47.4 (7.5 to 87.2)."},{"analysisId":"did-girls-pooled","checkType":"sensitivity","summary":"Weighting by population (pooled rates) gives +32.5 (state bootstrap 95% CI 2.0 to 74.7), smaller because large law states such as Florida grew less than smaller ones."},{"analysisId":"did-boys","checkType":"other","summary":"Boys also grew more in law states (+21.9, CI -15.3 to 59.1), so part of the girls' gain is a general rise in those states, not something specific to girls."},{"analysisId":"did-girls-share","checkType":"other","summary":"Girls' share of all participants rose 1.4 points more in law states (0.3 to 2.6), so girls gained relative to boys there."}]},{"id":"did-girls-2024-25","title":"Sensitivity: girls per 1,000, 2018-19 to 2024-25","question":"Does the result hold if the comparison ends in 2024-25?","operation":"As did-girls-main, ending in 2024-25.","scope":"24 law vs 22 no-law.","resultShape":"estimate","structuredResult":[{"label":"Change in girls per 1,000, 2018-19 to 2024-25, law minus no-law","estimate":46.7,"standardError":13.9,"ciLow":18.6,"ciHigh":74.7,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"+46.7 (95% CI 18.6 to 74.7); law states +19.6, no-law -27.1.","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-girls-excl-flag-wrestling","title":"Sensitivity: girls per 1,000 excluding flag football and wrestling","question":"Is the gap explained by girls' flag football and wrestling, which grew fastest and were sanctioned unevenly across states?","operation":"As did-girls-main after subtracting each state's girls' flag football and wrestling participants.","scope":"24 law vs 22 no-law; 2018-19 to 2025-26.","resultShape":"estimate","structuredResult":[{"label":"Change in girls per 1,000 excluding flag football and wrestling, law minus no-law","estimate":40.9,"standardError":18.6,"ciLow":3.4,"ciHigh":78.4,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"+40.9 (95% CI 3.4 to 78.4); law states +24.2, no-law -16.7. Ending 2024-25: +42.3 (15.0 to 69.5).","methodologicalNotes":["Sport columns extracted from the PDFs sum exactly to the NFHS national totals (wrestling 21,124 / 74,064 / 88,771; flag football 11,209 / 68,847 / 102,360 in 2018-19 / 2024-25 / 2025-26)."],"limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-girls-excl-flagged","title":"Sensitivity: excluding states with questionable NFHS figures","question":"Do states whose NFHS totals repeat a prior year or jump more than 25% in one year drive the result?","operation":"As did-girls-main without the flagged jurisdictions.","parameters":{"flaggedStates":["Ohio","Washington","Alabama","Connecticut","Mississippi","Louisiana","Kentucky","Arkansas","Maine","Delaware","Alaska","Vermont","District of Columbia"]},"scope":"19 law vs 16 no-law.","resultShape":"estimate","structuredResult":[{"label":"Change in girls per 1,000, flagged states excluded, law minus no-law","estimate":39,"standardError":10.8,"ciLow":16.8,"ciHigh":61.1,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":35}],"displayResult":"+39.0 (95% CI 16.8 to 61.1).","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-girls-excl-enjoined","title":"Sensitivity: excluding laws blocked in court","question":"Does the result change without Idaho, Utah and Arizona, whose laws were enjoined for some or all students?","operation":"As did-girls-main without those three states.","scope":"21 law vs 22 no-law.","resultShape":"estimate","structuredResult":[{"label":"Change in girls per 1,000, enjoined-law states excluded, law minus no-law","estimate":47.4,"standardError":19.7,"ciLow":7.5,"ciHigh":87.2,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":43}],"displayResult":"+47.4 (95% CI 7.5 to 87.2).","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-girls-pooled","title":"Sensitivity: population-weighted rates","question":"Does weighting by population change the result?","operation":"Change in pooled girls per 1,000 (law group) minus change in pooled rate (no-law group); 95% interval from 5,000 state bootstrap draws.","scope":"24 law vs 22 no-law; 2018-19 to 2025-26.","resultShape":"estimate","structuredResult":[{"label":"Change in pooled girls per 1,000, law minus no-law","estimate":32.5,"ciLow":2,"ciHigh":74.7,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Pooled rates; percentile state bootstrap, 5,000 draws","n":46}],"displayResult":"+32.5 (95% CI 2.0 to 74.7); law group 370.1 to 401.8 (+31.8), no-law 453.4 to 452.7 (-0.8).","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"placebo-girls-pre-period","title":"Placebo: the same comparison before any law (2015-16 to 2018-19)","question":"Were the future law states already gaining faster before the laws?","operation":"As did-girls-main for 2015-16 to 2018-19, when no state had such a law.","scope":"24 future-law vs 22 no-law.","resultShape":"estimate","structuredResult":[{"label":"Change in girls per 1,000, 2015-16 to 2018-19, future-law minus no-law","estimate":-16,"standardError":11,"ciLow":-38.2,"ciHigh":6.2,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"-16.0 (95% CI -38.2 to 6.2): the future law states were not gaining faster beforehand.","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-boys","title":"Comparison: boys per 1,000, 2018-19 to 2025-26","question":"Did boys' participation also grow faster in law states?","operation":"As did-girls-main with boys per 1,000 boys aged 14-17.","scope":"24 law vs 22 no-law.","resultShape":"estimate","structuredResult":[{"label":"Change in boys per 1,000, law minus no-law","estimate":21.9,"standardError":18.5,"ciLow":-15.3,"ciHigh":59.1,"ciLevel":0.95,"unit":"participants per 1,000 boys aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"+21.9 (95% CI -15.3 to 59.1); law states +30.7, no-law +8.8.","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-girls-share","title":"Comparison: girls' share of all participants","question":"Did girls gain relative to boys in law states?","operation":"As did-girls-main with girls / (girls + boys), in percentage points.","scope":"24 law vs 22 no-law; 2018-19 to 2025-26.","resultShape":"estimate","structuredResult":[{"label":"Change in girls' share of participants, law minus no-law","estimate":1.4,"standardError":0.5,"ciLow":0.3,"ciHigh":2.6,"ciLevel":0.95,"unit":"percentage points","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"+1.4 points (95% CI 0.3 to 2.6); law states +1.1, no-law -0.4. Excluding flagged states: +1.8 (0.8 to 2.8).","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-girls-percent","title":"Comparison: percent change in girls per 1,000","question":"How large is the gap in percent terms?","operation":"As did-girls-main using each state's percent change.","scope":"24 law vs 22 no-law; 2018-19 to 2025-26.","resultShape":"estimate","structuredResult":[{"label":"Percent change in girls per 1,000, law minus no-law","estimate":10.1,"standardError":4.2,"ciLow":1.6,"ciHigh":18.5,"ciLevel":0.95,"unit":"percentage points","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"Law states +10.9% on average, no-law +0.9%; difference +10.1 points (95% CI 1.6 to 18.5).","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"did-specs-compared","title":"Law-state minus no-law-state change, across specifications","question":"How robust is the gap in girls' participation between law and no-law states across specifications, and how does it compare with boys and with the period before the laws?","operation":"Collects the estimates of the individual saved analyses for charting.","scope":"See each row.","resultShape":"estimate","structuredResult":[{"spec":"Main: 2018-19 to 2025-26","label":"Main: 2018-19 to 2025-26","estimate":46,"standardError":18.6,"ciLow":8.4,"ciHigh":83.5,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46},{"spec":"Ending 2024-25","label":"Ending 2024-25","estimate":46.7,"standardError":13.9,"ciLow":18.6,"ciHigh":74.7,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46},{"spec":"Without flag football and wrestling","label":"Without flag football and wrestling","estimate":40.9,"standardError":18.6,"ciLow":3.4,"ciHigh":78.4,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46},{"spec":"Without questionable NFHS figures","label":"Without questionable NFHS figures","estimate":39,"standardError":10.8,"ciLow":16.8,"ciHigh":61.1,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":35},{"spec":"Without court-blocked laws","label":"Without court-blocked laws","estimate":47.4,"standardError":19.7,"ciLow":7.5,"ciHigh":87.2,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":43},{"spec":"Placebo: 2015-16 to 2018-19, before any law","label":"Placebo: 2015-16 to 2018-19, before any law","estimate":-16,"standardError":11,"ciLow":-38.2,"ciHigh":6.2,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46},{"spec":"Boys (per 1,000 boys)","label":"Boys (per 1,000 boys)","estimate":21.9,"standardError":18.5,"ciLow":-15.3,"ciHigh":59.1,"ciLevel":0.95,"unit":"participants per 1,000 boys aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":46}],"displayResult":"Main: 2018-19 to 2025-26: +46 (8.4 to 83.5); Ending 2024-25: +46.7 (18.6 to 74.7); Without flag football and wrestling: +40.9 (3.4 to 78.4); Without questionable NFHS figures: +39 (16.8 to 61.1); Without court-blocked laws: +47.4 (7.5 to 87.2); Placebo: 2015-16 to 2018-19, before any law: -16 (-38.2 to 6.2); Boys (per 1,000 boys): +21.9 (-15.3 to 59.1)","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"state-changes","title":"Change by state, 2018-19 to 2025-26","question":"In which states did girls' participation per 1,000 rise or fall?","operation":"Per-state rates in 2018-19 and 2025-26 and their difference.","scope":"All 51 jurisdictions.","resultShape":"table","structuredResult":[{"state":"Texas","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":407.9,"girlsPer1000_2025_26":436.9,"changeGirls":29,"changeBoys":-9.2,"flaggedData":false},{"state":"California","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":363.4,"girlsPer1000_2025_26":393.7,"changeGirls":30.3,"changeBoys":10,"flaggedData":false},{"state":"New York","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":382.4,"girlsPer1000_2025_26":322.2,"changeGirls":-60.2,"changeBoys":-69.3,"flaggedData":false},{"state":"Illinois","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":435.4,"girlsPer1000_2025_26":451.1,"changeGirls":15.7,"changeBoys":-2.2,"flaggedData":false},{"state":"Ohio","group":"law","lawFirstYear":"2024-25","girlsPer1000_2018_19":483.4,"girlsPer1000_2025_26":538.7,"changeGirls":55.3,"changeBoys":-24.9,"flaggedData":true},{"state":"Pennsylvania","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":494.6,"girlsPer1000_2025_26":485.3,"changeGirls":-9.3,"changeBoys":4.7,"flaggedData":false},{"state":"Michigan","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":503.4,"girlsPer1000_2025_26":507.6,"changeGirls":4.2,"changeBoys":34.7,"flaggedData":false},{"state":"Florida","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":286.1,"girlsPer1000_2025_26":263.2,"changeGirls":-22.9,"changeBoys":-34.8,"flaggedData":false},{"state":"New Jersey","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":538.1,"girlsPer1000_2025_26":503,"changeGirls":-35.1,"changeBoys":-52.3,"flaggedData":false},{"state":"Minnesota","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":830.2,"girlsPer1000_2025_26":727.4,"changeGirls":-102.8,"changeBoys":17.6,"flaggedData":false},{"state":"Massachusetts","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":634.7,"girlsPer1000_2025_26":610.7,"changeGirls":-24,"changeBoys":-3.6,"flaggedData":false},{"state":"North Carolina","group":"law","lawFirstYear":"2023-24","girlsPer1000_2018_19":336.3,"girlsPer1000_2025_26":318.7,"changeGirls":-17.6,"changeBoys":11.5,"flaggedData":false},{"state":"Georgia","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":268.4,"girlsPer1000_2025_26":316.6,"changeGirls":48.2,"changeBoys":10.6,"flaggedData":false},{"state":"Wisconsin","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":507.1,"girlsPer1000_2025_26":512.1,"changeGirls":5,"changeBoys":13.9,"flaggedData":false},{"state":"Virginia","group":"policy","lawFirstYear":null,"girlsPer1000_2018_19":364.6,"girlsPer1000_2025_26":382.7,"changeGirls":18.1,"changeBoys":-2.7,"flaggedData":false},{"state":"Missouri","group":"law","lawFirstYear":"2023-24","girlsPer1000_2018_19":471,"girlsPer1000_2025_26":520.8,"changeGirls":49.8,"changeBoys":-13.3,"flaggedData":false},{"state":"Indiana","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":359.5,"girlsPer1000_2025_26":370.1,"changeGirls":10.6,"changeBoys":5.3,"flaggedData":false},{"state":"Washington","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":450.3,"girlsPer1000_2025_26":536.7,"changeGirls":86.4,"changeBoys":53,"flaggedData":true},{"state":"Iowa","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":706.7,"girlsPer1000_2025_26":741.2,"changeGirls":34.5,"changeBoys":-38,"flaggedData":false},{"state":"Colorado","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":438.2,"girlsPer1000_2025_26":443.1,"changeGirls":4.9,"changeBoys":-3.6,"flaggedData":false},{"state":"Alabama","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":399.3,"girlsPer1000_2025_26":570.7,"changeGirls":171.4,"changeBoys":193.7,"flaggedData":true},{"state":"Arizona","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":289.4,"girlsPer1000_2025_26":320.1,"changeGirls":30.7,"changeBoys":29.2,"flaggedData":false},{"state":"Maryland","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":345.7,"girlsPer1000_2025_26":363.4,"changeGirls":17.7,"changeBoys":1.3,"flaggedData":false},{"state":"Oklahoma","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":377.3,"girlsPer1000_2025_26":409.1,"changeGirls":31.8,"changeBoys":31.2,"flaggedData":false},{"state":"Connecticut","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":553.9,"girlsPer1000_2025_26":543.6,"changeGirls":-10.3,"changeBoys":35.6,"flaggedData":true},{"state":"Tennessee","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":244.3,"girlsPer1000_2025_26":270.6,"changeGirls":26.3,"changeBoys":9.1,"flaggedData":false},{"state":"Mississippi","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":514.9,"girlsPer1000_2025_26":696.6,"changeGirls":181.7,"changeBoys":132.6,"flaggedData":true},{"state":"Louisiana","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":411.7,"girlsPer1000_2025_26":346.4,"changeGirls":-65.3,"changeBoys":46.6,"flaggedData":true},{"state":"Kansas","group":"law","lawFirstYear":"2023-24","girlsPer1000_2018_19":553.5,"girlsPer1000_2025_26":618.9,"changeGirls":65.4,"changeBoys":4.9,"flaggedData":false},{"state":"Kentucky","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":443.3,"girlsPer1000_2025_26":620.6,"changeGirls":177.3,"changeBoys":216.6,"flaggedData":true},{"state":"Oregon","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":453.9,"girlsPer1000_2025_26":445.2,"changeGirls":-8.7,"changeBoys":59.5,"flaggedData":false},{"state":"South Carolina","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":297.6,"girlsPer1000_2025_26":309.6,"changeGirls":12,"changeBoys":12.7,"flaggedData":false},{"state":"Nebraska","group":"law","lawFirstYear":"2025-26","girlsPer1000_2018_19":637.7,"girlsPer1000_2025_26":638.9,"changeGirls":1.2,"changeBoys":-61.4,"flaggedData":false},{"state":"Arkansas","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":341.2,"girlsPer1000_2025_26":432.8,"changeGirls":91.6,"changeBoys":43.8,"flaggedData":true},{"state":"Utah","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":284,"girlsPer1000_2025_26":351.8,"changeGirls":67.8,"changeBoys":50.6,"flaggedData":false},{"state":"Maine","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":779.5,"girlsPer1000_2025_26":703.1,"changeGirls":-76.4,"changeBoys":-44.4,"flaggedData":true},{"state":"New Mexico","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":396.9,"girlsPer1000_2025_26":426.9,"changeGirls":30,"changeBoys":63.9,"flaggedData":false},{"state":"Idaho","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":428.2,"girlsPer1000_2025_26":436.5,"changeGirls":8.3,"changeBoys":-19.1,"flaggedData":false},{"state":"Nevada","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":273.3,"girlsPer1000_2025_26":236,"changeGirls":-37.3,"changeBoys":-50.2,"flaggedData":false},{"state":"New Hampshire","group":"law","lawFirstYear":"2024-25","girlsPer1000_2018_19":615.1,"girlsPer1000_2025_26":609.4,"changeGirls":-5.7,"changeBoys":-6.7,"flaggedData":false},{"state":"West Virginia","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":328,"girlsPer1000_2025_26":366.4,"changeGirls":38.4,"changeBoys":-19,"flaggedData":false},{"state":"Hawaii","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":507.3,"girlsPer1000_2025_26":524.1,"changeGirls":16.8,"changeBoys":8.5,"flaggedData":false},{"state":"Montana","group":"law","lawFirstYear":"2021-22","girlsPer1000_2018_19":553,"girlsPer1000_2025_26":582.2,"changeGirls":29.2,"changeBoys":27.1,"flaggedData":false},{"state":"South Dakota","group":"law","lawFirstYear":"2022-23","girlsPer1000_2018_19":592.6,"girlsPer1000_2025_26":663.8,"changeGirls":71.2,"changeBoys":61.9,"flaggedData":false},{"state":"Rhode Island","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":643.9,"girlsPer1000_2025_26":618.6,"changeGirls":-25.3,"changeBoys":0.9,"flaggedData":false},{"state":"Delaware","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":532.8,"girlsPer1000_2025_26":476.6,"changeGirls":-56.2,"changeBoys":-48.7,"flaggedData":true},{"state":"North Dakota","group":"law","lawFirstYear":"2023-24","girlsPer1000_2018_19":673.1,"girlsPer1000_2025_26":665.5,"changeGirls":-7.6,"changeBoys":-4.8,"flaggedData":false},{"state":"Alaska","group":"policy","lawFirstYear":null,"girlsPer1000_2018_19":540.5,"girlsPer1000_2025_26":579.7,"changeGirls":39.2,"changeBoys":-103,"flaggedData":true},{"state":"Wyoming","group":"law","lawFirstYear":"2023-24","girlsPer1000_2018_19":594.9,"girlsPer1000_2025_26":618.4,"changeGirls":23.5,"changeBoys":-12.6,"flaggedData":false},{"state":"Vermont","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":428.4,"girlsPer1000_2025_26":655.3,"changeGirls":226.9,"changeBoys":217,"flaggedData":true},{"state":"District of Columbia","group":"noLaw","lawFirstYear":null,"girlsPer1000_2018_19":588,"girlsPer1000_2025_26":578.9,"changeGirls":-9.1,"changeBoys":-53,"flaggedData":true}],"displayResult":"Girls per 1,000 fell in 4 of 24 law states (Florida, North Carolina, Louisiana, North Dakota) and in 12 of 22 no-law jurisdictions. Median change: law +31.3, no-law -8.9.","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"cohort-estimates","title":"By year the law took effect","question":"Is the gap similar for each wave of laws?","operation":"As did-girls-main for each cohort; the 2023-24 cohort uses 2022-23 as its last pre-law year.","scope":"Each cohort vs 22 no-law.","resultShape":"estimate","structuredResult":[{"label":"Laws first applied 2021-22 (9 states), 2018-19 to 2025-26","estimate":62.2,"standardError":27.7,"ciLow":2.8,"ciHigh":121.7,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":31},{"label":"Laws first applied 2022-23 (10 states), 2018-19 to 2025-26","estimate":42.6,"standardError":23.8,"ciLow":-7.2,"ciHigh":92.5,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":32},{"label":"Laws first applied 2023-24 (5 states), 2022-23 to 2025-26","estimate":11.5,"standardError":35.2,"ciLow":-64.1,"ciHigh":87.1,"ciLevel":0.95,"unit":"participants per 1,000 girls aged 14-17","method":"Difference-in-differences of state-level changes; 95% Welch t interval, states as the unit","n":27}],"displayResult":"Laws first applied 2021-22 (9 states), 2018-19 to 2025-26: +62.2 (2.8 to 121.7); Laws first applied 2022-23 (10 states), 2018-19 to 2025-26: +42.6 (-7.2 to 92.5); Laws first applied 2023-24 (5 states), 2022-23 to 2025-26: +11.5 (-64.1 to 87.1)","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times.","Cohorts are small; the 2023-24 cohort has 5 states and only three post-law years."],"executedAt":"2026-10-23T19:00:00Z"},{"id":"later-adopters","title":"States whose laws took effect in 2024-25 or 2025-26","question":"What happened to girls' participation in Ohio, New Hampshire and Nebraska after their laws?","operation":"Rate in the last pre-law year and in 2025-26, beside the no-law mean change over the same years.","scope":"Ohio, New Hampshire, Nebraska.","resultShape":"table","structuredResult":[{"state":"Ohio","lastPreLawYear":"2023-24","girlsPer1000Pre":424.4,"girlsPer1000_2025_26":538.7,"change":114.3,"noLawMeanChangeSamePeriod":41.9},{"state":"New Hampshire","lastPreLawYear":"2023-24","girlsPer1000Pre":618.3,"girlsPer1000_2025_26":609.4,"change":-8.9,"noLawMeanChangeSamePeriod":41.9},{"state":"Nebraska","lastPreLawYear":"2024-25","girlsPer1000Pre":617.7,"girlsPer1000_2025_26":638.9,"change":21.2,"noLawMeanChangeSamePeriod":26.3}],"displayResult":"Ohio +114.3 (but its 2022-23 and 2023-24 NFHS figures are identical, so its base year is suspect); New Hampshire -8.9 vs no-law +41.9; Nebraska +21.2 vs no-law +26.3.","limitations":["Observational comparison: states chose these laws, and the law states differ from the others (region, politics, school sports culture). The estimate is a difference in trends, not a measured effect of the laws.","NFHS counts are self-reported by state associations; some states repeat a prior year's figures or jump more than 25% in a year.","Participation entries, not unique athletes: a girl in three sports counts three times.","One or two post-law years; single states; Ohio's pre-law figures appear carried forward."],"executedAt":"2026-10-23T19:00:00Z"}]}