These studies are from the National Bureau of Economic Research (NBER). They are all gated, but summaries are accessible.
Do Medicaid/SCHIP expansions improve child reading scores? Probably not. There is a gain of 3 points on a base of 239 in the reading (but not math) score of the 4th and 8th graders taking the National Assessment of Educational Progress.
To save the children, reduce childcare subsidies. Childcare subsidies may harm child development, increasing behavior problems and decreasing reading and math scores.