The GiveWell Blog

Followup on Fryer/Dobbie study of “Harlem miracle”

I recently posted about a new, intriguing study on the Harlem Children’s Zone. It’s now been a little over a week since David Brooks’s op-ed brought the study some major attention, and I’ve been keeping up with the reaction of other blogs. Here’s a summary: Methodology: unusually strong I haven’t seen any major complaints about…

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Fryer and Dobbie on Harlem Children’s Zone: What they found

The Fryer/Dobbie study on the Harlem Children’s Zone is, in my view, an extremely important work that should seriously affect how donors think about the cause of promoting equality of opportunity in the U.S. (Longtime readers of this blog know that we don’t often say something like this.) This post will simply summarize what it…

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Positive but underwhelming voucher study

The third-year evaluation of a federally funded school voucher program in D.C. has recently been released (H/T Joanne Jacobs). We’ve written before that past voucher studies have shown extremely underwhelming (if any) effects, and at first glance this report would seem to be a change in the pattern: “The evaluation found that the OSP improved…

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Mistargeted microfinance?

There are many studies attempting to gauge microloans’ impact on borrowers, but most suffer from the problem of selection bias: by comparing participants and non-participants, they may be picking up other differences between these groups (for example, people who participate in microloan programs may be wealthier to begin with, so a study showing that they…

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Trachoma: An example of the need for long-term monitoring

When is a measured program-impact not a real impact? When it doesn’t last. A study published today in PloS NTDs evaluated the impact of four doses of azithromycin (one every 6 months), and monitored trachoma prevalence throughout the drug administration period and for 2 years after the last dose. In the first 24 months (from…

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