The Peacock's Tail -- Analogy of the week from Brad DeLong

From an excellent post on the growth of financial services:

The obverse of that fall is the rise of a peculiar piece of the service sector: the growth of finance, insurance, and real estate transactions (i.e., the paper shuffling and the exchanging, not the construction). It was supposed to be the high-productivity sector of the future. It has turned out to be the equivalent of a peacock's tail--damnably awkward and reducing your mobility and survival characteristics, but fascinating to the peahen, for a while at least.