The American Dream is moving further and further out of reach for millions in the U.S.

Why it matters: That promise is essential to American identity — and its erosion will affect how we live, work and vote for decades to come.

What's happening: It's increasingly unaffordable to buy a home or pay for college — and millennials, many of whom entered the job market at the height of the recession, are feeling the crunch.

The cost of higher education is ballooning. From 1978 to 2017, the Consumer Price Index grew fourfold, but the price of college increased 14-fold, according to research by Ana Hernández Kent, a policy analyst at the St. Louis Fed.

is ballooning. From 1978 to 2017, the Consumer Price Index grew fourfold, but the price of college increased 14-fold, according to research by Ana Hernández Kent, a policy analyst at the St. Louis Fed. The price of homes is rising much faster than incomes. Per a study by real estate company Clever that looked at census data from 1960 to 2017, U.S. housing prices have skyrocketed 121%, but incomes have increased just 29%.

is rising much faster than incomes. Per a study by real estate company Clever that looked at census data from 1960 to 2017, U.S. housing prices have skyrocketed 121%, but incomes have increased just 29%. Wage growth has been sluggish. Wage growth in the U.S. has decelerated since 1979 — and the middle and low ends of the wage spectrum have been hardest hit, the Economic Policy Institute reports. Average hourly wages for all American workers grew 2.2% from 1947 to 1979, but just 0.7% from 1979 to the present.

Wage growth in the U.S. has decelerated since 1979 — and the middle and low ends of the wage spectrum have been hardest hit, the Economic Policy Institute reports. Average hourly wages for all American workers grew 2.2% from 1947 to 1979, but just 0.7% from 1979 to the present. And socioeconomic mobility is at an all-time low. As we've reported, fewer Americans are faring better than their parents did — and more are doing worse. Per a recent UPenn study, around 60% of people born in the 1940s did better than their parents, compared with 40% of those born in the 1980s.

Why we're still confident: There remain bright spots and reasons for optimism, experts say — and America's reputation as a land of promise continues to beckon people from abroad, whose homelands offer less mobility.

Americans are more entrepreneurial than ever before. There were 3.4 million applications to start businesses last year, a record number, per the U.S. Census Bureau.

The idea that people can try out ideas, turn them into businesses, "and see if they catch has always been a driving force of pursuing the American Dream," Holly Wade, research director at the National Federation of Independent Business, a right-leaning small business lobbying group, tells Axios.

But the number of budding companies that researchers estimate will turn into job creators — a measure of success — hasn't returned to its pre-financial crisis level. "There is recovery in the quantity but not so much in the quality of business applications," according to the U.S. Census Bureau.

The U.S. homeownership rate is back to pre-recession levels, despite the rising cost of homes.

Around 65% of American families own homes. That's up from recession-era lows and mirrors the U.S. homeownership rate of much of the 20th century, says Mike Fratantoni, chief economist at the Mortgage Bankers Association.

That rate could climb even higher. "In the past six months, there's been a pickup in the pace of home construction," he says. "The average size and cost of homes are coming down a bit."

Still, the homeownership rate among millennials remains quite low. Around 44% of older millennials — those born between 1980 and 1989 — own homes, which is 4 percentage points lower than what would be expected based on older generations, Kent says.

The bottom line: "Sink or swim by your own strength is not applicable to this generation as it was with previous ones," says Kent. "The tide is much stronger."