For over 150 years, many of history's great economists, from Karl Marx to John Maynard Keynes, predicted that machines would usher mankind into a scholarly fantasy of enlightened leisure. Robots would, they argued, serve all of our needs while we spent the days reading classics, debating philosophy, and indulging in fine art.

Well, it turns out that the prophecy was half right. Many prime age workers enjoy unprecedented levels of leisure, but—and here’s the other half—they would apparently rather doze off into a midday nap watching the Desperate Housewives of New Jersey than debate the merits of Plato's Republic.

The U.S. government's annual survey of how Americans spend their day, the American Time Use Survey, continues to show that disaffected workers fill their extra free time sleeping and watching TV. Time spent on education, taking care of others, or self-improvement has not fully filled their free hours.

For decades, robots have slowly been replacing human work. For a time, the elimination of one type of work simply meant it was filled with another. For instance, as appliances automated the drudgery of homemaking, housewives threw in their aprons and increased their hours in the workforce—granting them more social and economic power. But we are getting to a point where less mundane work is needed, which is why the work week, on average, is shrinking for some.

In a recent Pew investigation of how robots would change the nature of work, Berkeley Professor Emeritus and Google's chief economist, Hal Varian, praised the robotic economy. His words are worth quoting at-length:

How unhappy are you that your dishwasher has replaced washing dishes by hand, your washing machine has displaced washing clothes by hand, or your vacuum cleaner has replaced hand cleaning? My guess is this ‘job displacement’ has been very welcome, as will the ‘job displacement’ that will occur over the next 10 years. The work week has fallen from 70 hours a week to about 37 hours now, and I expect that it will continue to fall. This is a good thing.

As such, the decrease in work hours has coincided with the smallest workforce in a generation. The labor participation rate is at a 36-year low. These citizens are not classified as "unemployed," but rather "disaffected," because they aren't even looking for work. With all that free time, tech utopians might expect disaffected workers to indulge in world-class education materials: watch free lectures from MIT's EdX, take up Apple's musical instrument instructor, Garage Band, or perhaps calmly debate the merits of a hot-button political issue in the comments section of The New York Times.

Indeed, in one of his epic tweetstorms, noted venture capitalist investor and Twitter philosopher king, Marc Andreessen, theorized about the utopia a shortened work week might herald.

So far, reality has been much different than Andreessen's thought experiment. The most likely people to engage in free online college lectures are those who already have a graduate degree or are high-income earners. The same is true for volunteering and political involvement.

In hindsight, this connection seems somewhat unsurprising: the traits that make one a life-long learner are also the ones that motivate them to climb higher up the economic ladder. And motivations aside, opportunity begets opportunity the way wealth begets wealth. But the implications of how we use leisure time go beyond missed chances for a civically engaged populus.

The Atlantic's Rebecca Rosen has described the dire mental-health effects of long-term unemployment. The number of those being treated for depression nearly doubles as time spent unemployed goes from two weeks to one year—it jumps from 11 percent to 19 percent. Nearly one-third of the long-term unemployed spend two hours or less socially with friends or family. She noted that one reader wrote to The Atlantic, explaining, "I look at my peers who are getting married and having children and generally living life and it's depressing. They've got jobs, health insurance, relationships, homes; I don't even have a real bed to sleep on."

As automation promises to usher us in to a world of less work, policymakers are beginning to address the potential economic fallout. Both Hillary Clinton and Google's Larry Page have suggested that government-subsidized part-time work is one solution. But, it may not be enough. Our schools and institutions will likely have to come up with solutions for the many people who are not needed to participate in the economy.

At a Google talk last year, Hillary Clinton acknowledged that she did not have a good solution to the automated economy. “I don’t have a quick, glib answer to give you,” she said. “But I can tell you that I’d like to have any thoughts from all of you, because you are making this new world.”