Tyler Cowen reports on some disturbing research. For example,

Donors to charities, it seems, do not behave rationally. Increasing evidence shows that donors often tolerate high administrative costs, fail to monitor charities and do not insist on measurable results

Tyler and other professors probably will not like this, but I think that the most irrational phenomenon in charitable giving is donations to colleges and universities. To me, giving money to Harvard and Swarthmore is like making charitable contributions to Microsoft and Exxon.