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Essays in public economics (Elwell 2019)

Review Guidelines

Absence of conflict of interest. 

Citation

Elwell, J. P. (2019). Essays in public economics (Doctoral dissertation, Cornell University). ProQuest Dissertations and Theses (13880779)

Highlights

  • The study's objective was to examine the impact of federal and state Medicaid expansions on hours worked per week, annual earned income, and participation in other public safety net programs among families with children ages 0-17. 

  • The authors used a difference-in-differences analysis to assess whether expansions in Medicaid eligibility were associated with changes in hours worked per week, annual earned income, and participation in other public safety net programs among families with children ages 0-17. To conduct their analysis, the authors used data from the data from the Annual Social and Economic Supplement to the Current Population Survey (CPS-ASEC), focusing on the period 1980 – 2010. 

  • The study’s findings suggest that Medicaid expansions were associated with more hours worked per week, higher annual earned incomes, and higher levels of participation in social safety net programs.  

  • The quality of causal evidence presented in this report is low. This means we are not confident that the estimated effects are attributable to Medicaid expansions; other factors are likely to have contributed. 

Intervention Examined

Medicaid expansion

Features of the Intervention

Medicaid was created in 1965 to provide health insurance to low-income families. States implement their own Medicaid programs and are granted some flexibility in determining eligibility requirements so long as these requirements meet minimum eligibility standards set by the federal government. By 1990, all states were required to cover children under age six in families below 133 percent of the federal poverty line, as well as older children in families with incomes below 100 percent of the federal poverty line. The establishment of the Children’s Health Insurance Program (CHIP) in 1997 further expanded Medicaid eligibility for children. Throughout the period of study (1980 – 2010), there was considerable variation in rates of Medicaid eligibility both over time and across states.  

Features of the Study

The authors used a difference-in-differences analysis to examine the impact of federal and state Medicaid expansions on labor market outcomes and participation in safety net programs that support families with children. Study findings examined the impact of overall Medicaid eligibility – which incorporated eligibility expansions implemented at both the Federal and state level – and the impact of Federal Medicaid eligibility – which looked only at expansions implemented at the Federal level.   

Using annual data from the Annual Social and Economic Supplement to the Current Population Survey (CPS-ASEC) over the period 1980 – 2010, the authors used a statistical analysis to assess whether the share of a state’s children deemed eligible for Medicaid in a particular year was associated with labor market outcomes and safety net program participation.  

The analysis sample consisted of 53,098 families with children, each of which is observed once in the CPS-ASEC data. Labor market outcomes included labor supply, annual earned income, and hours worked per week. Safety net participation outcomes focused on four programs serving families with children: the Supplemental Nutrition Assistance Program (SNAP), cash welfare (prior to 1996, Aid for Families with Dependent Children; from 1996 on, Temporary Assistance to Needy Families), the Earned Income Tax Credit (EITC), and rental subsidies.  

Observed changes in a state’s share of children eligible for Medicaid, labor market outcomes, or participation rates for other safety net programs could result from changing demographics or economic shocks, rather than from Medicaid expansion. To address this possibility, the authors constructed a “fixed sample” that simulates Medicaid eligibility as if states’ demographic compositions had remained fixed at 1990 levels throughout the entire period of study (with income. The authors used this simulated measure of Medicaid eligibility as part of an instrumental variable analysis, to isolate changes in Medicaid eligibility that were due to Medicaid expansion, rather than due to underlying demographic or labor market shifts. 

Findings

Employment  

  • Study findings suggested a positive, statistically significant association between overall Medicaid eligibility and total weekly hours worked among family members. A 10 percentage point increase in a state’s overall Medicaid eligibility was associated with a 1.3 percent increase in the total hours worked by family members.  

  • The study found no evidence suggesting a statistically significant association between Federal Medicaid eligibility and total weekly hours worked among family members.  

Earnings and Wages 

  • Study findings suggested a positive, statistically significant association between overall Medicaid eligibility and total annual family labor income.  

  • The study found no evidence suggesting a significant association between Federal Medicaid eligibility and total annual family labor income. 

Public Benefits Receipt 

  • The study found no evidence suggesting a a statistically significant association between overall Medicaid eligibility and participation in SNAP, cash welfare programs, EITC, or rental assistance programs. 

  • Study findings suggested a positive, statistically significant association between Federal Medicaid eligibility and SNAP participation, cash welfare participation, and rental assistance participation.   

Considerations for Interpreting the Findings

The authors did not control for the gender of CPS respondents in their main analyses. Therefore, this study is not eligible for a moderate 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 control for the gender of CPS respondents in their main analyses. Patterns of employment, earnings, and program participation that vary by gender and family structure may not be fully accounted for in the study’s findings. A low causal evidence rating means that we are not confident the estimated effects are attributable to Medicaid expansions; other factors are likely to have contributed.  

Reviewed by CLEAR

November 2022