""Unfortunately, our investments in many early-childhood programs may be based on an inflated sense of their promise. Even our best efforts often produce only ephemeral gains.

We reviewed data from 67 high-quality interventions — all of which included some degree of pre-literacy and early math skill-building and most of which targeted economically disadvantaged children — and we found that the effects faded startlingly fast: falling by half within a year and by half again two years later.""


https://www.washingtonpost.com/posteverything/wp/2017/02/17/preschool-can-provide-a-boost-but-the-gains-can-fade-surprisingly-fast/?utm_term=.c9faaf5e446f