Using the data in MROZ from Mroz $(1987),$ we estimate the following linear probability model, where $428$ of the $753$ women in the sample report were in the labor force at some point during $1975$:

Here, let inlf $($in the labor force$)$ be a binary variable indicating labor force participation by a married woman during $1975$: inlf$=1$ if the woman reports working for a wage outside the home at some point during the year, and zero otherwise. We assume that labor force participation depends on other sources of income, including husband$$s earnings $($nwifeinc$,$ measured in thousands of dollars$),$ years of education $($educ$),$ past years of labor market experience $($exper$),$ age, number of children less than six years old $($kidslt$6),$ and number of kids between $6$ and $18$ years of age $($kidsge$6).$

$($i$)$ Provide the interpretation of the coefficient on exper. Why experience has been entered as a quadratic?

$($ii$)$ Holding other factors fixed, estimate the change in the probability and the point at which the past experience has no effect on the probability of labor force participation.

$($iii$)$ Provide the interpretation of the kidslt$6$ and kidsge$6$ coefficients.$)2$