In the Depression, smart college students flocked into civil engineering to design the highway, bridge and dam-building projects of those days. In the Sputnik era, students poured into the sciences as America bet on technology to combat the cold war Communist challenge. Yes, the jobs beckoned and the pay was good. But those careers, in their day, had other perks: respect and self-esteem.

Big shifts in the flow of talent can ripple through the nation and the economy for decades with lasting effect. The engineers of the Depression built everything from inter-city roads to the Hoover Dam, while the Sputnik-inspired scientists would go on, often with research funding from the Pentagon, to create the building-block innovations behind modern computing and the Internet.

Today, the financial crisis and the economic downturn are likely to alter drastically the career paths of future years. The contours of the shift are still in flux, in part because there is so much uncertainty about the shape of the economic landscape and the job market ahead.

But choosing a career is a guess about the future in which economics is only part of the calculation. Prestige, peer expectations and the climate of public opinion also matter. And early indications suggest new career directions that are tethered less to the dream of an immediate six-figure paycheck on Wall Street than to the demands of a new public agenda to solve the nation’s problems.