Absence of conflict of interest.
Highlights
- The study's objective was to examine the impacts of state and local minimum wage increases on hours worked by low-wage workers.
- The author used a difference-in-difference design to estimate the impacts of state and local minimum wage increases on hours worked by low-wage workers, using data from the Current Population Survey. They used a statistical model to compare changes in hours worked by low-wage workers who were subject to a minimum wage increase to changes in hours worked by similar workers who were not subject to a minimum wage increase.
- The study did not find a statistically significant relationship between state and local minimum wage increases and hours worked by low-wage workers.
- The quality of causal evidence presented in this report is low because the author did not ensure that the groups being compared were similar before the intervention. This means we would not be confident that any estimated effects would be attributable to state and local minimum wage increases, other factors are likely to have contributed. However, the study did not find statistically significant effects.
Intervention Examined
Features of the Intervention
State and local minimum wage increases above the federal minimum wage have been implemented in many communities across the country. Policymakers and researchers are interested in understanding how minimum wage increases affect individuals' incentives to work full time. Previous research into the effects of minimum wage increases on hours worked has found mixed results.
Features of the Study
The author used a difference-in-difference design to estimate the impacts of state and local minimum wage increases on hours worked by low-wage workers. Using data from the Current Population Survey, the author limited the study sample to hourly paid workers aged 16 or older with wages at or below the local minimum wage and no tips, overtime pay, or commissions at the fourth-month or eight-month CPS interview. The treatment group included survey respondents who were subject to a minimum wage increase between their fourth-month and eighth-month CPS interviews. The comparison group included survey respondents who were not subject to a minimum wage increase between their fourth-month and eighth-month CPS interviews. The author used a statistical model to compare hours worked by low-wage workers who were subject to a minimum wage increase to changes in hours worked by similar workers who were not subject to a minimum wage increase.
Findings
Employment
- The study did not find a statistically significant relationship between state and local minimum wage increases and hours worked by low-wage workers.
Considerations for Interpreting the Findings
The author did not account for preexisting differences between the groups before the intervention or include sufficient control variables. These preexisting differences between the groups—and not state and local minimum wage increases—could explain any observed differences in outcomes. Therefore, the study is not eligible for a moderate causal evidence rating, the highest rating available for nonexperimental designs.
Causal Evidence Rating
Research Guidelines
Review Guidelines: Causal Evidence Guidelines