Crowding out: are relations between international health aid and government health funding too complex to be captured in averages only?

In today's Lancet, Lu and colleagues1 show that for every dollar of international health aid provided to governments, government health funding falls by US$0·43—1·14. Irrespective of whether this outcome is named fungibility or crowding out,2 mean estimates from many countries suggest a pattern. Without questioning the mean findings of today's study, we argue that explicit policy choices are behind crowding-out effects, unfolding very differently dependent on the individual countries' situations. To try to understand why some countries make these choices that result in crowding-out effects, and not only whether they do, is of importance.