By the time children begin formal schooling, their experiences at home have already contributed to large variations in their math and language development, and once school begins, academic achievement continues to depend strongly on influences outside of school. It is thus essential that educational reform strategies involve primary caregivers. 

This paper critically reviews what we know about the long-term effects of parental leave and early childhood education programs. We find only limited evidence that expansions of parental leave durations improved long-run educational or labor market outcomes of the children whose parents were affected by them, perhaps because benefits are hard to measure or confined to sub-groups, or because leave entitlements were sufficiently long, even before recent extensions, to yield most potential benefits. 

Head Start is a federal early childhood intervention designed to reduce disparities in preschool outcomes. The first randomized experimental study of Head Start, the National Head Start Impact Study (NHSIS), found impacts on academic outcomes of .15 to .3 standard deviations measured at the end of the program year, although the estimated impacts were no longer significant when measured at the end of kindergarten or first grade.

Over the past two decades states have drastically increased their investments in pre-kindergarten programs. One major question about state investments in early childhood education programs is to what extent these initiatives create new child care options rather than crowd-out existing private child care options.

In practice, teacher turnover appears to have negative effects on school quality as measured by student performance. However, some simulations suggest that turnover can instead have large positive effects under a policy regime in which low-performing teachers can be accurately identified and replaced with more effective teachers.