University of Arkansas professor Jay Greene explains the results of a rigorous study of Head Start:

As I described last week, the Department of Health and Human Services has been sitting on an evaluation of the Head Start government run pre-school program. Well, today the study was released (and it?s not even a Friday!).

As the leaks suggested, the study found virtually no lasting effects to participation in Head Start. The study used a gold-standard, random assignment design and had a very large nationally representative sample. This was a well done study (even if it mysteriously took more than 3 years after data collection was complete to release the results).

For students who were randomly assigned to Head Start or not at the age of 4, the researchers collected 19 measures of cognitive impacts at the end of kindergarten and 22 measures when those students finished 1st grade. Of those 41 measures only 1 was significant and positive. The remaining 40 showed no statistically significant difference. The one significant effect was for receptive vocabulary, which showed no significant advantage for Head Start students after kindergarten but somehow re-emerged at the end of 1st grade.

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The long and short of it is that the government has a giant and enormously expensive pre-school program that has made basically no difference for the students who participate in it. And folks are proposing that we expand government pre-school to include all students. Those same folks have some bridges they?d like to sell.