Milton Friedman is still the clearest public voice on basic economics and public policy. In this video he explains why the idea that you can do good with other people's money is a popular fallacy.
Chris Coyne's forthcoming book with Stanford University Press, Doing Bad By Doing Good (2013) is a contemporary updating of this basic Friedman point about the ineffectiveness due to pervese incentives of spending other people's money, and more as Coyne explains in detail the knowledge problems, bureaucratic problems, and political power problems associated with humanitarian aid. Very excited to see Coyne's latest book in print.
HT: Michael Munger for the Friedman video.