Thirty-plus years ago, when I was a graduate student in economics, only the least ambitious of my classmates sought careers in the financial world. Even then, investment banks paid more than teaching or public service  but not that much more, and anyway, everyone knew that banking was, well, boring.

In the years that followed, of course, banking became anything but boring. Wheeling and dealing flourished, and pay scales in finance shot up, drawing in many of the nation’s best and brightest young people (O.K., I’m not so sure about the “best” part). And we were assured that our supersized financial sector was the key to prosperity.

Instead, however, finance turned into the monster that ate the world economy.

Recently, the economists Thomas Philippon and Ariell Reshef circulated a paper that could have been titled “The Rise and Fall of Boring Banking” (it’s actually titled “Wages and Human Capital in the U.S. Financial Industry, 1909-2006”). They show that banking in America has gone through three eras over the past century.

Before 1930, banking was an exciting industry featuring a number of larger-than-life figures, who built giant financial empires (some of which later turned out to have been based on fraud). This highflying finance sector presided over a rapid increase in debt: Household debt as a percentage of G.D.P. almost doubled between World War I and 1929.