Apparently there is a Gates Annual Letter which I read for the first time this year. You can read full letter here. Lots of good points. I would recommend reading the part on corruption. It goes on to show how important it is to identify problem in hand and not get lost in other details. Aim of aid, or any other expenditure for any work X, is to get the work done. Sure, we would like to have a corruption free society so that things are more efficient but what if corruption is there. Bill writes:

Suppose small-scale corruption amounts to a 2 percent tax on the cost of saving a life. We should try to reduce that. But if we can’t, should we stop trying to save lives?