Cambridge, Mass.

A WONDERFUL ride has come to an end. For several decades after World War II the economic statistics we care most about all rose together here in America as if they were tightly coupled. G.D.P. grew, and so did productivity — our ability to get more output from each worker. At the same time, we created millions of jobs, and many of these were the kinds of jobs that allowed the average American worker, who didn’t (and still doesn’t) have a college degree, to enjoy a high and rising standard of living.

Productivity growth slowed in the 1970s but revved up again in the 1990s and has stayed strong most years since. But as shown by the accompanying graph, which was first drawn by the economist Jared Bernstein, productivity growth and employment growth started to become decoupled from each other at the end of that decade. Bernstein calls the gap that’s opened up “the jaws of the snake.” They show no signs of closing.

We are creating jobs, but not enough of them. The employment-to-population ratio, or percentage of working-age people that have work, dropped over 5 points during the Great Recession, and has improved only half a point in the three and a half years since it ended [pdf].

As the jaws of the snake opened, wages suffered even more than job growth. Adjusted for inflation, the average U.S. household now has lower income than it did in 1997. Wages as a share of G.D.P. are now at an all-time low, even as corporate profits are at an all-time high. The implicit bargain that gave workers a steady share of the productivity gains has unraveled.