Robin Hanson wants someone to come out in favor of Mankiw's proposed "tall tax", which aims to redistribute the unearned windfall that tall people receive just because nature has decreed that they will tower over their peers. Peter Diamond has dismissed this argument because it relies on the premise that models which produce ridiculous conclusions should be thrown out. Mankiw's reasonable response is that if we don't throw out models which produce ridiculous conclusions, then we're just cherry picking in order to validate our priors. This would tend to vitiate any claims economics might make to being a science.
However, I am tall. Therefore, I know this is a stupid tax. Let's think about why:
1) It confuses income with utility. Yes, I get to be tall. On the other hand, I can't find any clothes that fit. I spend ridiculous amounts of time trying to contort my body to fit standard automobiles, airplanes, busses, and so forth. I also suffer from many physical ailments associated with being tall: poor circulation in my hands and feet, foot cramps (my feet are too small for my height), back trouble, and a nasty case of bursitis which I acquired because no one told me that very tall women with long legs for their height should never, ever take up cross country running.
Also, my height completely crushed my childhood dreams of becoming a jockey.
2) The income is not distributed evenly among the tall: it goes almost entirely to men who got their full height very early. Why should I pay more in taxes just because my cousin can afford a Lexus?
3) Height can be associated with deadly conditions. You've got Marfans or a pituitary tumor. You're going to die young. Hello, here's a special tax on your condition, just in case your life was not already difficult enough.
4) We already have a very good proxy for earning extra income, which is . . . the extra income. Presumably, the progressive income tax is already taxing the tall for being tall, while possibly also giving them discounts for other conditions that have lowered their earnings potential.
5) I already pay quite enough in taxes, thank you very much.
6) I have noticed that the kind of economists who spend a lot of time proving that tall people are smarter, earn more, and are also probably better conversationalists and fantastic in the sack, tend to also be the kind of economists who spend a lot of time shopping at Rochester Big and Tall. This qualifies my faith in their results, and therefore, my willingnes to alter tax policy accordingly.
7) I really pay a lot in taxes.