Absence of conflict of interest.
Citation
Highlights
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The study’s objective was to examine the impact of state ERA ratification on labor market outcomes for women.
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The authors used a difference-in-differences design to estimate the impacts of ERA ratification on employment, earnings, hours worked, and labor force participation for women. Using data from the 1970-2012 Current Population Survey (CPS) March Supplement, the authors used a statistical model to compare labor market outcomes for women and men, before and after ERA ratification.
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The study suggests a positive relationship between ERA ratification and employment for women, but reported no evidence of a relationship between ERA ratification and labor force participation, hours worked, or salary for women.
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The quality of causal evidence presented in this report is low because the authors did not ensure that the groups being compared were similar before the intervention. This means we are not confident that the estimated effects are attributable to ERA ratification; other factors are likely to have contributed.
Intervention Examined
Equal Rights Amendment (ERA)
Features of the Intervention
The Equal Rights Amendment (ERA) was first introduced in Congress in 1923 and initially gained approval from the U.S. House and Senate in 1972. By 1982, 35 state legislatures had ratified the policy, which did not meet the required three-fourths rule to become a part of the Constitution. The amendment has been the focus of some more recent legislative activity, with two additional states ratifying the amendment in 2018.
Features of the Study
The authors observe labor market outcomes for individuals using data from the Current Population Survey (CPS) over the period 1970 to 2012. The sample consists of working age adults, aged 20 to 65, who live in Standard Metropolitan Statistical Areas (SMSAs). The treatment group consists of women residing in states that had ratified the ERA. The comparison group consists of women and men residing in states that had not ratified the ERA. The authors utilized a difference-in-differences research design that compared labor market outcomes for women to outcomes for men, before and after ERA enactment.
Findings
Employment
- This study suggests a positive relationship between ERA ratification and employment rates and no relationship between ERA ratification and labor force participation rates or hours worked.
Earnings and Wages
- The study found no evidence of a relationship between ERA ratification and earnings for women.
Considerations for Interpreting the Findings
The authors compared labor market outcomes for women to those for men before and after ERA ratification. CLEAR’s guidelines require that the authors must observe outcomes for multiple periods before the intervention to rule out the possibility that participants had increasing or decreasing trends in the outcomes examined before the intervention occurred. That is, if participants who had increasing employment, education, or wages were more likely to reside in or move to states that ratified the ERA, we would anticipate further increases in these outcomes over time, even if ERA enactment had no impact. Without knowing the trends before ERA enactment, we cannot rule this out. Therefore, the study is not eligible for a moderate causal evidence rating, the highest rating available for nonexperimental designs.
Causal Evidence Rating
The quality of causal evidence presented in this report is low because the authors did not ensure that the groups being compared were similar before the intervention. This means we are not confident that the estimated effects are attributable to ERA; other factors are likely to have contributed.