To see why TBTF also can mean TBTM — too big to manage — read “What’s Inside America’s Banks?” in the January/February issue of the Atlantic. Frank Partnoy and Jesse Eisinger argue that banks are not only bigger but also “more opaque than ever.” And regulations partake of the opacity: The landmark Glass-Steagall Act of 1933, separating commercial banking from investment banking, was 37 pages long; the 848 pages of the 2010 Dodd-Frank law may eventually be supplemented by 30 times that many pages of rules. The “Volcker rule” banning banks from speculating with federally insured deposits is 298 pages long.

There is no convincing consensus about a correlation between a bank’s size and supposed efficiencies of scale, and any efficiencies must be weighed against management inefficiencies associated with complexity and opacity. Thirty or so years ago, Brown says, seven of the world’s 10 largest banks were Japanese, which was not an advantage sufficient to prevent Japan’s descent into prolonged stagnation. And he says that when Standard Oil was broken up in 1911, the parts of it became, cumulatively, more valuable than the unified corporation had been.

Brown is fond of the maxim that “banking should be boring.” He suspects that within the organizational sprawl of the biggest banks, there is too much excitement. Clever people with the high spirits and adrenaline addictions of fighter pilots continue to develop exotic financial instruments and transactions unknown even in other parts of the sprawl.