Over at the Library of Economics and Liberty, Duke political science chair Michael Munger has a real gem of an essay lucidly explaining why democracy, which caters to the median voter, won't produce innovation, which is created by bets with long odds by risk-takers on the fringe.
For political decisions, "good" simply means what most people think is good, and everyone has to accept the same thing. In markets, the good is decided by individuals, and we each get what we choose. This matters more than you might think. I don't just mean that in markets you need money and in politics you need good hair and an entourage. Rather, the very nature of choices, and who chooses, is different in the two settings.
That part's not very funny, but most of the essay is. So if you like your political economy at once weird and crystal clear, do check it out.