Franco Modigliani died last month, at home in Cambridge, Massachusetts. He was 85, a wonderful man who lived a wonderful life. Re-reading his autobiography, I was struck by what an adventure that life had been.

There was his happy childhood in Rome in the 1920s, as the younger of two doted-upon brothers in a well-to-do family in Rome; the death of his pediatrician father when he was 14; the flight from Mussolini's Fascists, first to Paris, then in 1939 with his young wife to New York (the Modigliani family had fled to Italy several centuries before when the Jews were expelled from Spain).

There was the great good fortune of meeting Jacob Marschak at The New School in Manhattan, who persuaded him to learn some math, just in time to join the early formalizers of Keynesian economics; the witch-hunt at the University of Illinois, when McCarthyite forces led by former football star Red Grange hounded Modigliani and many other professors from the campus; the vitality of the years at the Carnegie Institute (now Carnegie-Mellon University) in Pittsburgh, where his best ideas developed; the death of his collaborator Richard Brumberg.

Then came the happy landing in 1960 at the Massachusetts Institute of Technology, and all the rest, including the Nobel Prize in 1985; the canny investing, especially the advice given f MIT; the long-term involvement in Italian politics at the highest levels; the home and sailboat on Martha's Vinyard; the well-adjusted extended family.

The man cast a long shadow. Indeed, it is not too much to say that Modigliani did for Boston in finance what his fellow MIT professor Salvatore Luria did in biology -- that is, he (and a handful of other local economists, including Paul Samuelson, Robert Merton, Fischer Black, John Lintner and John Williams) kept the city abreast in the great game as a world center of high-tech finance.

I was struck, too, by how long ago all of this happened.

It reminded me of Max Planck's famous apothegm, to the effect that science progresses funeral by funeral.

Ten years ago, I collected a bunch of newspaper columns in a book. I found it easy to divide the economists into "the older generation" and "the younger generation" and the rest into "neighbors," "critics," "practitioners" and so on. The ink was barely dry before I realized there were three generations in 20th-century economics, not two.

I have come to think that they can be described pretty well in terms of the great challenges that world affairs posed to economics in the crucial years when these young men and women were entering the profession and beginning to make their way. There were developments internal to economics all the while, of course, and in many ways these are more important for understanding what actually happened.

But the great epochal events are what we have in common. They shaped the public reception of the profession, as well as what went on inside.They are, roughly speaking, the generation of the Great Depression (and World War II), the generation of the Cold War, and the generation of Perestrokia, as restructuring was known in the former Soviet Union. The forces turned out to be global.

It is easy enough to pick out that first generation of 20th-century economists. We had long known that something important had happened in economics in the 1930s. There had been a "Keynesian Revolution." Less visibly, there had been a Modern Program, a movement among economists who were determined to build a solid axiomatic foundation beneath a discipline whose 19th-century sills were becoming pretty shaky.

Then the Swedes established a Nobel Award for Economics in 1969, diluting (slightly) the world's most famous brand and touching off arguments that have continued ever since. One inarguable result, however, was a terrific first-draft intellectual history of economics' "Greatest Generation."

There were Keynesians (Paul Samuelson, John Hicks, Wassily Leontief, Lawrence Klein, Robert Solow, James Tobin, Franco Modigliani). There were the Moderns (Kenneth Arrow, John Nash, Tjalling Koopmans, Herbert Simon, Gerard Debreu, Trygve Haavelmo, Maurice Allais). There were Chicagoans (Milton Friedman, George Stigler, Theodore Schultz, Friedrich Hayek, Ronald Coase, James Buchanan, Harry Markowitz, Merton Miller, Gary Becker, Robert Lucas, James Heckman). And there were those who were honored in elsewhere than in Stockholm (Joan Robinson, George Dantzig, Albert Hirschman, Gordon Tullock, Janos Kornai).

The generation of the Cold War consists of those economists who went to graduate school in the 1950s and 1960s and there found themselves sitting at the feet of giants who, it was said, had won World War II with slick management techniques and thereafter eliminated the business cycle. These young economists took up the challenge of explaining prosperity without peace, and otherwise extending the "neoclassical synthesis" that their elders had announced. Broadly speaking, they can be divided into two classes: properly respectful and disobedient.

A few of members of this Cold War generation are familiar names by now, if not exactly household words. Martin Feldstein. Joseph Stiglitz, Robert Barro, Robert Shiller, Alan Blinder, Jagdish Bhagwati, Stanley Fischer, the late Rudiger Dornbusch.

Nobel Award winners in the Cold War cohort include Robert Lucas, Gary Becker, James Mirrlees, Robert Merton, James Heckman, Daniel McFadden, Amartya Sen and George Akerlof.

Many other Boomers and pre-Boomers are alive and kicking and deserving of more fame than they enjoy now -- Avinash Dixit, Elhanan Helpman, Karl Shell, Orley Ashenfelter, Franklin Fisher, Peter Diamond, Sandy Grossman, Dale Jorgenson, Edmund Phelps, Oliver Hart, Eugene Fama, Truman Bewley, David Kreps, Andreu Mas-Collell, Jean Geanakoplos, Edward Prescott, Paul David, Herbert Scarf, Oliver Williamson, Hugo Sonnenschein, William "Buz" Brock, Duncan Foley, Paul Milgrom, Christopher Sims, David Colander, Stephen Ross, John Roberts, Michael Jensen, Olivier Blanchard, Robert Hall, William Nordhaus, Jerry Hausman, Hal Varian, Robert Gordon and Stanley Engerman to name only some of the most obvious.

There are some great adventures, especially in the lives of those who came of age in the 1960s. Martin Feldstein and Peter Diamond, for example, have been crossing swords and mobilizing legions on issues of public finance since they met at Oxford forty years ago. Now they are having their turns as back-to-back presidents of the American Economic Association.

The late Zvi Griliches (1930-1999) should be remembered for having taught so successfully. So should Otto Eckstein (1926-1984) and Sherwin Rosen (1938-2001).

But it is the third generation that really interests me, the Perestroika generation. These are the students who went to graduate school in the 1970s -- after Prague, after Vietnam, after Watergate. Some are well known already. John Taylor, Jeffrey Sachs, Jean Tirole, Paul Krugman, A. Michael Spence, Lawrence Summers, N. Gregory Mankiw, Paul Romer, Thomas Sargent, Andrei Shleifer. There are many, many other younger economists in the wings. The best-known of this cohort are having their public policy adventures now. The work with which the won their fame within the profession lies fifteen years or more in the past.

A fair amount of confusion arises at this point. For the really interesting generation of economists today is the first generation of the 21st Century -- in other words, those who are just embarking on their careers. Nothing is clearer from the record than that most of the work that eventually changes the field is done by economists who are in their late twenties and thirties. Yet even the achievements of the Perestroika generation are not yet very well understood.

Indeed, often the members of the "Greatest Generation" are the ones who still get the ink, simply because they are the best-known names. Franco Modigliani was writing letters to The New York Times the week he died -- and getting them published. This despite the indignities of old age, which included, in Modigliani's case, a careless publisher decorating the inside book jacket of his autobiography with a photograph of the youthful Peter Drucker.

I have long believed that the American press was too inattentive to developments in technical economics -- which is to say, for all the remarkable applied work that has gone on in Wall Street and Washington (and their counterparts cities around the world), university economics. The Nobel Foundation and the Royal Swedish Academy of Sciences are providing an invaluable service by writing a careful version of the history of thought, albeit with a lag of twenty-five or thirty years.

(Here, too, the influence of the generations is poweful. Assar Lindbeck was secretary of the prize committee for its first 25 years. After he stepped down, leadership passed to the next generation of Swedish economists. The frontier for prize-winning developments seemed to suddenly jump at least a decade, from the 1950s to the early 1970s.)

Following this shifting frontier used to be my job, and I think I have come up with a way of getting at it within the confines of EconomicPrincipals.com. So I am going to take a crack at it. Not next week, for next week the Nobel Award will be announced on Wednesday afternoon. There will be more fascinating news about developments in economics, albeit news in the rearview mirror.

Obituaries make good reading. So do stories about Nobel Awards and presidential addresses. And in economics, as in any science, you can't write about current developments without having in mind, more or less constantly, the generations of economists who have gone before. But these are exciting times. Shouldn't we have more stories about what is going on in economics now?

I'll begin in mid-October.