Emil O W Kirkegaard

Not apriori aparent. If anything, might be opposite as kids with bad sight keep falling behind. That would lead to underestimated effect 3/n

You can of course say "Would love to see this replicated in a in RCT". But incorrect to say "Study doesn't show that". 4/n

In absence of RCT evidence, best available evidence should move our priors to some degree. If it moves by zero, prior may be too strong. 5/n

My prior is very strong that these programs generally don't work. Extremely flimsy evidence does little to change that.

What do you mean by "these programs"?

Educational interventions, especially these hyped ones targeted at poor/dull kids. I already linked to the Headstart study.

There is a ton if evidence including from RCTs about education interventions that matter a lot. For US, see e.g. work by @dynarski. 1/3

Here is the RCT you wanted on eye glasses btw: among 19,000 students with randomized access to glasses in China. http://www.sciencedirect.com/science/article/pii/S0304387816300402 … 2/3