Do preschool investments depreciate and fadeout or result in dynamic complementarities? An assessment using the Head Start Impact Study

In this article, we use data from the Head Start Impact Study to assess the effect of attending preschool at ages three and four on cognitive and behavioral skills and whether these effects depreciate and fadeout or result in dynamic complementarities that affect skills. Evidence from our analyses suggests that effects of preschool depreciated significantly within a year and that there were no positive dynamic complementarities that offset depreciation. Furthermore, our findings suggest that only a small fraction of the accumulation of cognitive and behavioral skills from ages three to four and four to five can be explained by preschool attendance limiting its ability to address racial and socioeconomic disadvantages in child development.