All that new technology does what?

Tyler Cowen's e-book, "The Great Stagnation," has become the most debated nonfiction book so far this year.

Cowen's core point is that up until sometime around 1974, the American economy was able to experience awesome growth by harvesting low-hanging fruit.

There was cheap land to be exploited.

There was the tremendous increase in education levels during the postwar world. There were technological revolutions occasioned by the spread of electricity, plastics and the car.

But that low-hanging fruit is exhausted, Cowen continues, and since 1974, the United States has experienced slower growth, slower increases in median income, slower job creation, slower productivity gains, slower life-expectancy improvements and slower rates of technological change.

Cowen's data on these slowdowns is compelling and has withstood the scrutiny of the online reviewers. He argues that our society, for the moment, has hit a technological plateau.

But his evidence can be used to tell a related story. It could be that the nature of technological change isn't causing the slowdown but a shift in values.

But in an affluent information-driven world, people embrace a postmaterialist mind-set. They realize they can improve their quality of life without actually producing more wealth.

For example, imagine a man we'll call Sam, who was born in 1900 and died in 1974. Sam entered a world of iceboxes and horse-drawn buggies.

He died in a world of air conditioning and moon landings. His life was defined by dramatic material changes, and he worked feverishly hard to build a company that sold brake systems. He wasn't the most refined person, but he understood that if he wanted to create a secure life for his family he had to create wealth.

Sam's grandson, Jared, was born in 1978. Jared wasn't really drawn to the brake-systems business, which was withering in America.

He works at a company that organizes conferences. He brings together fascinating speakers for lifelong learning. He writes a blog on modern art and takes his family on vacations that are more daring and exciting than any Sam experienced.

But many of these things are produced outside the conventional monetized economy. Most of the products are produced by people working for free. They cost nothing to consume.

They don't even create many jobs. As Cowen notes in his book, the automobile industry produced millions of jobs, but Facebook employs about 2,000, Twitter 300 and eBay about 17,000.

It takes only 14,000 employees to make and sell iPods, but that device also eliminates jobs for those people who make and distribute CDs, potentially leading to net job losses.

In other words, as Cowen makes clear, many of this era's technological breakthroughs produce enormous happiness gains, but surprisingly little additional economic activity.

For Sam, income and living standards were synonymous, but for Jared, they have diverged. He is more interested in the latter than the former.

Because he doesn't fully grasp the increasingly important distinction between wealth and standard of living, he has the impression that he is also getting richer. As a result, he lives beyond his means.

As Cowen notes, many of our recent difficulties stem from the fact that many Americans think they are richer than they are.

Jared is also providing much less opportunity for those down the income scale than his grandfather did. Sam was more hardhearted, yet his feverish materialism created more jobs.

Jared worries about that. He also worries that the Chinese and others have a material drive that he and his cohort lack. But he's not changing.

For the past few decades, Americans have devoted more of their energies to post-material arenas and less and less, for better and worse, to the sheer production of wealth.