LONG BEACH, CA—“Could it be that the best years of American economic growth are behind us?” asked Robert J. Gordon, a professor of social sciences at Northwestern University, during a session of this week's TED2013 Conference. The session, called "Progress Enigma," asked speakers to tackle the concept of progress in a slowing American economy. Gordon's question is a scary one, made more terrifying by the last few years, when growth has been negative in some sectors. In his talk today, Gordon named four “headwinds” that confront the nation—demographics, education, debt, and inequality—which point to an ebbing American economy. Combined, these four factors cut growth in half, and innovation is needed to offset this trend. But that innovation is not likely to materialize, said Gordon. If we have less innovation over the next 50 years, there will be even less growth.

From 1891 to 2007, American economic growth was 2.0 percent per year. Now that it's slowing, we can no longer expect generational improvements in living, he argued. What's at the root of this slowdown? One factor is the very significant drop of young men in the labor force. Some of this is caused by technological improvements, such as factory robots that displace workers. Birth rates are down, too. We have too many old people who are retiring and not enough young people entering the labor market, Gordon said.

Education costs are also a massive impediment to growth, Gordon told the audience. College completion rates are 15 percent lower in the US than in Canada, and fewer people can afford to go. At the same time, personal and government debt are stifling American economic growth. When there is no growth, this debt becomes a massive burden. Finally, inequality, the fourth headwind, compounds these problems: growth in the lower income brackets is practically non-existent. Right now we see only 0.8 percent growth for the bottom 99 percent.

Gordon then turned to history to explain the origins of our expectations of economic growth. The past American century was a phenomenal period of increasing wealth, and there is simply no guarantee that it should continue as such, he said. Electricity has been central to our American century, Gordon noted. Suddenly vertical cities were possible, and urban populations went from 25 percent of the total population to 75 percent in only a few decades. And electricity had far-reaching effects: women’s liberation was helped in part by the efficiencies made possible by electricity (refrigeration meant not needing to shop every day, laundry could be done much more quickly, etc.). Women also used to be primarily responsible for carrying water in to the home, but pumps and plumbing changed this.

On a more general level, the light bulb made us all more productive and more intelligent—we could read and work at night! The combustion engine also unleashed massive change. Suddenly one-third of agricultural land could be used for population growth rather than feeding horses. “The problem we face is that all of these great inventions—we have to match them in the future. My prediction is that we are not going to match them,” Gordon said.

This ultimately means that the 2.0 percent growth we’ve enjoyed to date is more likely to look like 0.2 percent growth in the future. The only way to push past it, Gordon concluded, would be to focus on addressing these headwinds.

The present is just a bump in the road

But Erik Brynjolfsson, a professor at the MIT Sloan School of Management and the director of the MIT Center for Digital Business, took the stage next and stated plainly, “Growth is not dead.”

Electricity, he said, is a “general purpose technology” that creates economic growth by driving complementary technologies, and technology alone is not enough. Rather, generation after generation has to reinvent their productivity in light of these new general purpose technologies. We see this in the generational gaps of progress between the advent of a new technology and the productivity it brings.

“Today, productivity is at an all time high,” he noted. Worldwide incomes are growing faster than ever in history, and that’s not even the whole picture. Many of the gains we are making are hard to measure. Minds, brains, and knowledge are huge benefactors of recent progress, but it's difficult, if not impossible, to measure that. Then there’s the explosion of free services that empower us. Zero price means zero weight in GPD stats. So how do we factor in the goods and services brought by, for example, the Internet?

Brynjolfsson argued that the "new machine age" is digital, replicated perfectly at zero cost, almost instantaneously—abundance has arrived. The new age is also exponential. “Computers get better, faster, than everything, ever,” he said.

The new machine age is combinatorial in that ideas do not get used up but rather create building blocks for new innovations. “The most important invention is machine learning,” Brynjolfsson told the crowd. IBM’s Watson recently showed this. It started as a weak system, but it improved faster than any human could. It will soon apply to legal, medical, and law enforcement jobs. “The full implications of the new machine age will take a century to play out,” he said, and it’s hard not to see those implications powering growth.

But problems lie ahead, Brynjolfsson conceded. Productivity is growing, but productivity is separating from employment, he said. Wealth is separating from work.

“Technology is racing ahead but leaving more and more people behind,” he noted. He pointed to tax preparation specialists as a quick example. Seventeen percent of them have lost jobs in recent years thanks to $40 programs like TurboTax, which produces wealth for fewer people.

We must try to find shared prosperity.

Brynjolfsson believes that the new machine age can be dated to the day when Gary Kasparov lost to IBM’s Deep Blue. But today, Kasperov showed that teams of people working with computers can beat the computers alone. Brynjolfsson's solution? We have to find the answer in teamwork.

Throughout the two talks, progress would sometimes be defined as GDP growth, sometimes as a measure of standards of living, and at other times the creation of new technologies. In the end, as is so often the case with TED debates, there was no consensus on the big picture. But both speakers agreed on one point: the labor force is being left behind, and we must work to solve the educational and population problems that confront the United States.