Famed development economist Esther Duflo answers reader questions at the Managing Globalization blog. Students with an interest in development will find it an excellent read.

One questioner asks Duflo about the virtues and vices of randomized control trials. Her response:

The more we experiment, the more information we have. That can never be bad! If it were the case that the pricing of bednets has different impacts on their use in different countries, then it seems to be we would want to know that, no? And it would seem that we would need very rigorous evidence to really know it. If we get several different results in different contexts, it will eventually help us understand what matters.

More information is of course better, but this seems like an opportune moment to remember another precept of economics: opportunity cost. Randomized trials are expensive and time-consuming, and it’s worth specifying under what circumstances (if any) they ought to be absorb the time and energy of the world’s best and brightest development economists.

Esther gets at that question in more detail in a new paper with Abhijit Banerjee and a slightly older one with Michael Kremer. Both are required reading for any burgeoning empiricists.

Read Esther’s full Q&A here.