Marginal Tax Rate Series

Our Marginal Tax Rate research series examines the range of effective marginal tax rates for low-income households and common benefit program “bundles.”  We also focus on families receiving child care subsidies (CCDF) and Temporary Assistance for Needy Families (TANF).

What Happens When Low-Income Households Increase Their Earnings?
Effective marginal tax rates are a natural and inevitable consequence of benefits that target low-income but not middle-income households. Program benefits that cover basic needs are designed to decline as earnings increase. High marginal tax rates––where most of additional earnings are offset by lost benefits––may be a work disincentive.
 
What are marginal tax rates and program cliff effects? Why are high marginal tax rates hard to predict and overcome? What can we do about high marginal tax rates?
 
Among households with children just above poverty, the median marginal tax rate is high (51 percent). Households with children are more likely to face high marginal tax rates than households without children. Among households with children below 200 percent of poverty, the most common combination of benefits is SNAP + EITC + Child Tax Credits (CTC) + Medicaid/Children’s Health Insurance Program (CHIP).
 
Marginal tax rates are highest for CCDF households just above poverty. Only three percent of CCDF households would lose their entire child care subsidy (i.e., the child care “cliff”) following a $2,000 earnings increase.
 
Including cliff effects, about 7 percent of TANF households (100,000) were estimated to have high marginal tax rates (70 percent or more). 
 
This technical appendix provides a detailed description of our data and methodology.