I just finished More than Good Intentions by Dean Karlan and Jacob Appel.

This book mainly covers the application of randomized controlled tests (RCTs) to foreign aid programs. It illustrates a number of common practices, and how they fared under the tests, and how they were improved in order to maximize benefit to the recipients.

It also goes a little into behavioural economics, but that is more of a minor theme that is mentioned but not strongly developed.

Overall a very interesting book, and an encouraging one. Foreign aid has not been particularly successful over the last fifty years, but using techniques like these gives me hope that it will be more successful over the next fifty.