Vote Selling vs. Voting
Economist Greg Mankiw, former chair of Bush's Council of Economic Advisers, thinks free markets are pretty good, but not free markets in your vote. Fellow economist Bryan Caplan thinks that the real problem of externalities Mankiw sees isn't just with selling votes, but with voting itself.
Caplan's October reason cover story on "The Four Bone-Headed Biases of Stupid Voters."