Which Statement About the Estimated Effects of the Earned Income

Which statement about the estimated effects of the Earned Income Tax Credit (EITC) on labor supply is TRUE?

A) The 1986 expansion of the EITC did not increase the labor market participation of single mothers.
B) The 1986 expansion of the EITC did not affect the number of hours worked by those already in the labor force.
C) The 1986 expansion of the EITC reduced the number of hours worked by those in the labor force.
D) Researchers were not able to study the effects of the 1986 expansion of the EITC.