Conflict of Interest
Greg Mankiw argues that a utilitarian should support a height tax. I haven't read the argument, but, like all excellent arguments it is obvious once stated. Height is correlated with income, therefore taxing the rich is more egalitarian that a poll tax. Taxing the rich and rebating the money lump sum is egalitarian. Utilitarians are egalitarian because we think that the marginal utility of consumption declines in consumption (I think it declines a lot so I am both a utilitarian and very egalitarian even if many philosophy majors (not including Matt Yglesias) think that is a contradiction in terms).
People can't change their height to avoid the tax. Or rather won't. One could cut ones feet off to reduce one's tax burden, but that is not likely to be a problem at all.
Thus the height tax is an egalitarian redistribution without distortions.
I like to think that I am as close to a vulgar add up the utils utilitarian as any sane intelligent person who has heard the standard arguments can be (that is not very very close). I wish I could argue in favor of the height tax, but I can't, because I passed through an over privilidged life accumulating only 5 feet and 7 inches if I stretch real hard. A rare exception which doesn't invalidate the rule, but which does palsey my fingers as I type.
Prof Mankiw has no such problem.