File under dealing effectively with poverty is hard.
Brookings has issued a report by Grover J. Whitehurst on a study of Tennessee’s Voluntary Pre-K Program (TN-VPK).:
TN‐VPK is a full day pre-k program for four‐year‐olds from low-income families. It has quality standards that are high and in keeping with those proposed by the Obama administration under Preschool for All, including the requirement of a licensed teacher in each classroom, no more than 10 children per adult, and an approved and appropriate curriculum.
The study, conducted by a stellar team of researchers at Vanderbilt, began in 2009. It is a randomized trial (the gold standard for evaluating program impacts) involving about 3,000 four-year-olds whose parents had applied for their admission to oversubscribed TN-VPK programs. A lottery was used to select those to whom an offer of admission was made. Those winning the lottery constitute the intervention group. Those losing the lottery constitute the control group. Only about a quarter of children in the control group found their way into other center-based programs such as Head Start or private pre-k, so the study compares groups that are very different in their levels of access to early childhood education.
In Whitehurst's assessment the results are discouraging:
I see these findings as devastating for advocates of the expansion of state pre-k programs. This is the first large scale randomized trial of a present-day state pre-k program. Its methodology soundly trumps the quasi-experimental approaches that have heretofore been the only source of data on which to infer the impact of these programs. And its results align almost perfectly with those of the Head Start Impact Study, the only other large randomized trial that examines the longitudinal effects of having attended a public pre-k program. Based on what we have learned from these studies, the most defensible conclusion is that these statewide programs are not working to meaningfully increase the academic achievement or social/emotional skills and dispositions of children from low-income families. I wish this weren’t so, but facts are stubborn things. Maybe we should figure out how to deliver effective programs before the federal government funds preschool for all.
Read it all. Here's a key chart and description:
An effect size that is larger than zero favors the participants in the TN-VPK whereas a negative effect size favors the control group. As the figure shows, seven of the outcomes are negative, with one (quantitative concepts) being statistically significant.