Stories and Science

Universal Preschool has been in the news recently. I remember a very compelling Planet Money episode from a couple years ago. It tells a very convincing story.

Over at Brookings, Russ Whitehurst dives into the science. You really should go read it. Here is his conclusion.

This doesn’t mean that we ought not to spend public money to help families with limited financial resources access good childcare for their young children. After all, we spend tax dollars on national parks, symphony orchestras, and Amtrak because they make the lives of those who use them better today. Why not childcare?

It does mean that we need public debate that recognizes the mixed nature of the research findings rather than a rush to judgment based on one-sided and misleading appeals to the preponderance of the evidence.

It is very hard to separate the stories we tell ourselves from the way we evaluate science. Would that more policies were based on strong science instead of stories.

[update]: Some background on the links. Whitehurst goes into more details, but here’s the 5-second version.

The Perry Preschool Project was an experiment run in 1962. It found dramatically higher quality of life measurements for the children who got access to the preschool classes. For example, 42% higher monthly income, 46% lower chance of having spent time in jail, 44% higher high school graduation rate.

The Planet Money episode talks with an Oklahoma legislator who did reading on the Perry study and similar ones and thought it was one of the best ways the state could invest its money. Specifically, that there were tremendous returns available. It’s an interesting story of how the policy actually came into being.

Whitehurst discusses the available studies and shows that the ones, like Perry, that have very positive effects have methodological problems, or are unlikely to scale up to a state- or nation-wide level. Studies that don’t have methodological problems show little or no effect.

The story: small investments in preschool can yield great rewards for society.

The science: despite early results pointing in that direction, better designed studies show that the results are unlikely to be as promised by the story.