Child Tax Credit (CTC) gives partially refundable tax credit to filers who have children younger than 17 years old and who owe tax. For individuals whose income is within the subsidy range, the trapezoid structure of CTC provides work incentives when the substitution effects outweigh the income effects. In this paper, I examine the effects of CTC on maternal labor supply by difference-in-difference design and simulation method. I show that \$1000 increase in average CTC are associated with 1.13 percentage points increase in labor force participation and 0.37 hour increase in weekly working hours for single mothers. This labor supply effect is driven by mothers whose youngest child is between 3 and 5 years old. I didn't find any impacts on the labor supply of single mothers from higher socioeconomic status, implying no negative effect on employment.
JEL Classification: I12 , I18 , J18