H7.

There is a hypothesis that the expansion of welfare programs in the 1970s encouraged single motherhood. (a) To test this hypothesis, one method, we discussed in class, compared states. What variation at the state level did we discuss? Write down a regression equation we used for this analysis, and interpret the coefficient of interest. (b) What was the sign of the coefficient of interest? Does this sign support the hypothesis? Note: You don't need to worry about causality yet. (c) Would the results of the regression in (b) be causal? Explain why or why not. (d) We discussed an extension to the method in (a) that addresses the concerns you raised in (c). What is the control variable/s? Explain what this variable controls for in the regression. (e) What is the sign of the coefficient of interest, once you include the control you discussed in (d)? (f) Based on this evidence, what conclusion do you make about the hypothesis at the beginning of the question.