I can eradicate more misery per dollar by far over there than over here. It's clear that if the goal is to buy the most good with the few dollars I have to spend, I'll need to shop where things are cheapest. A useful start might be the Copenhagen Consensus, in which a panel of eight distinguished economists (including three Nobel Prize winners) prioritized the world's needs in terms of bang for the buck. In other words, given that the developed world might spend some billions in aid in the years to come, how could it best spend that money to do the most good? The best bets, the economists said, were battling AIDS, providing micronutrients, liberalizing trade, and combating malaria. Fighting malnutrition, funding various water projects, and lowering the cost of starting a business came next.