9. Consider the raw data from the BLS on labor market outcomes broken down by gender and parental status, which will be given.

a. Is having a child under age 18 associated with more or less labor force participation among men and women? Is it associated with higher or lower earnings?

b. Provide 2 examples of omitted variables that could make the raw differences in earnings between mothers and non?mothers biased estimates of the causal impacts of motherhood on female earnings. For each variable, describe the story you have in mind (i.e., how it is correlated with motherhood and with earnings), and if you think its omission will cause the raw gap to be biased upward or downward compared to the true causal impact of motherhood.

c. Do you think these variables will also bias the estimates effects of fatherhood on men in the same ways? Explain.

Start with raw correlations: BLS work hours With children < age 18 No children < age 18 Impact of having children Percent impact Labor force participation Women Men 72.9% 51.3% +21.6ppt +42% 92.9% 60.9% +32ppt +52% Part-time employment Women Men 19.5% 23.3% -3.8ppt -16% 4.4% 14.7% -10.3ppt -70%