The Economist has recently had several articles talking about the efficacy of preschool programmes.
From Human Capital:
Mr Obama's appears to be drawing heavily on the work of James Heckman, a Nobel-laureate economist at the University of Chicago, who in turn draws heavily on two relatively small studies, one focusing on the Perry Preschool Project and the other on the Carolina Abecedarian Project. Charles Murray, a conservative sociologist, sums up the standard complaint against generalising from the results of these projects:
The samples were small. Perry Preschool had just 58 children in the treatment group and 65 in the control group, while Abecedarian had 57 children in the treatment group and 54 in the control group. In both cases the people who ran the program were also deeply involved in collecting and coding the evaluation data, and they were passionate advocates of early childhood intervention. These shortcomings do not automatically disqualify the results, but think of it this way: if the case against the efficacy of early childhood interventions rested on two studies with small samples conducted by people who were openly hostile to such interventions, no one would pay any attention to them.
I think Mr Murray's right. So then what? Katherine Mangu Ward of Reason writes:
If only we had some kind of large scale well-tracked pilot program that could give us some information about whether that is a good idea. Oh wait! We do! It's called Head Start, the $8 billion federal program catering to more than 1 million low-income kids.Better still, the federal government has done a huge study, tracking 5,000 kids and comparing them to kids who did not have access to Head Start.The findings are not impressive. A 2010 analysis of that group found that the cognitive, health, parenting, and social benefits of the program had vanished by first grade. And a 2012 look at the third grade outcomes was even less heartening, with no discernible academic gains and teachers reporting slightly more behavioral problems in the Head Start kids.
This is basically the state of the debate over subsidised pre-school for families who can't otherwise afford it. If you favour the idea, you cite Mr Heckman on the Perry and Abecedarian results; if you oppose it, you cite the lacklustre performance of Head Start.
From Learning for the very young, there is the sense that it could be good, but nailing it down is hard:
The most recent report by the OECD, a rich-world think-tank, in 2009, found that 15-year-olds who had attended pre-schools for more than a year performed better (even accounting for socioeconomic background) than those who had attended for only a year or not at all. In Belgium, France and Israel pupils educated at pre-schools had much higher reading scores than those who had stayed at home. Yet establishing the precise link between time in pre-school and later achievement is difficult. .... Yet the key to success, if any, is unclear. Measuring other data, a report on pre-school availability and teaching standards called “Starting Well” (compiled for the Lien Foundation by the Economist Intelligence Unit, our sister company) placed Finland top (it scored direly in the OECD study). At least 98% of children aged five or six are in pre-school education there. Finland also dominates the overall league tables for education performance, so perhaps the scope for improvement is slight. Other enthusiastic providers of pre-school education like Sweden, Norway, France and Belgium and Denmark do not score particularly highly on attainment in later education, whereas Japan, which combines early-years provision with a fiercely competitive exam culture, excels. So too does South Korea, where the state until now has provided under half of pre-school places. So pre-school is no panacea, says Andreas Schleicher, who oversees the OECD’s big triennial PISA report on educational attainment. “Drilling children” in early years does not lead automatically to learning gains, he says.
Finally, in Social Mobility in America, they argue the chief effect is to help overcome socio-economic barriers. In arguing against an entrenched meritocracy (which essentially just becomes a new aristocratic class), The Economist suggests that early opportunities help select the best children early on, so that resources can flow to them.