More than two-thirds of Americans are dissatisfied with the way income and wealth are distributed in the U.S. economy, according to a new Gallup poll released this week. While that discontent is particularly high among Democrats (75 percent) and independents (70 percent), it is shared even by a majority of Republicans (54 percent).

Forty-three percent of independents and Democrats go even further, describing themselves as very dissatisfied.

Is that a problem? Maybe not. A certain degree of economic discontent is healthy and even necessary in a capitalist system. It’s the fuel on which the engine runs. If everyone was satisfied with his or her lot in life, the incentive to work hard, save, invest, invent and study would disappear, the economy would crash, and then where would we be? Complete economic satisfaction would be a very short-lived phenomenon.

On the other hand, if two-thirds of Americans now believe that the economy produces unfair results, it suggests a dangerous loss of faith in the system. I’d love to know how much that dissatisfaction has increased over time, but unfortunately, this is the first year Gallup has asked that question.

Since 2001, however, Gallup has asked a question that may help us get at the same sentiment: “How satisfied are you with the ability of Americans to get ahead by working hard?” That is, after all, the core of the American Dream. Do most Americans still believe it’s valid?

Yes, but barely. When Gallup asked the question back in 2001, 76 percent said they were satisfied that hard work would pay off with success. Today, it has fallen to 54 percent, a bare majority. And unfortunately, that rapid decline cannot be dismissed as an artifact of the Great Recession, because the decline was apparent even before the economy tanked. It is also confirmed by findings of other pollsters. According to a Rasmussen poll, for example, only 15 percent of Americans believe today’s children will be better off than their parents, while 61 percent disagree. That’s a pretty startling reversal of American optimism.

For years, economists have been reporting that economic mobility — a person’s ability to move up or down the economic ladder by dint of his or her own hard work — has been falling in the United States, and in fact is now lower here in “The Land of Opportunity” than in many other industrialized countries. The polling numbers tell us that the American people, through their own firsthand encounters with the modern economy, are coming to the same conclusion as the experts.

It’s important to note that advancement hasn’t become impossible — not by any means. A good work ethic, a college education and marriage to a spouse who has both a job and a degree boost your chances substantially. The problem is that even if you do everything right, the number of good-paying slots available in the modern American economy is measurably shrinking. Put bluntly, we are producing a lot more college graduates than jobs that require a college education.

“In 1970, fewer than 1 percent of taxi drivers and 2 percent of firefighters had college degrees, while now more than 15 percent do in both jobs,” a recent study by the Center for College Affordability reports.

Citing federal statistics, the study also reports that 24.6 percent of retail sales people and 16 percent of bartenders now have college degrees. Overall, 48 percent of the 41.7 million working Americans with college degrees have jobs that don’t require such degrees, and thus don’t pay like they do.

Again, it’s important to note that these are not just the result of the Great Recession, which means they aren’t temporary. These are trends that have been playing out for 40 years and show every sign of continuing. In essence, we’re trending toward a lottery economy. Getting a college education may buy you a ticket in the lottery, but the percentage of winners shrinks each year, even as the payoff from winning soars.

And those who lose out in that lottery still have college loans to pay back on an income that a high-school graduate could have gotten. The rules of the game are changing.

Of course, those of you with a 20-something back home already know all this.