International development is a major political priority in many countries, with billion-dollar budgets. But, as recently as 2006, the influential Center for Global Development published a damning report entitled 'When will we ever learn?', essentially arguing that the entire policy area had been built on a foundation of guesswork and good intentions.
In the two decades since then, a huge amount of work has been done to bring rigorous evidence to this complex and often values-laden political area. For the Science for Policy podcast, Marie Gaarder and Thomas Kelly from the International Initiative for Impact Evaluation cover all the bases: the evidence we have and the evidence we need, how it should be used, and what's still getting in the way.