Now, a Gallup poll of more than 2,000 American adults reveals that roughly half of Americans don't see college as a necessity.
In 2013, Gallup found that 70% of U.S. adults considered a college education to be "very important," 23% felt it was "fairly important" and 6% said it was "not too important."
In 2019, those figures have shifted to 51%, 36% and 13%, respectively.
The biggest shift can be seen among young adults between the ages of 18 and 29. In 2013, 74% of Americans in this age group said college was "very important," but by 2019, just 41% said the same thing.
Stephanie Marken, author of the new analysis and executive director of education research at Gallup, says the changes are cause for concern.
"The decline in overall perceived importance is expected, given increased concerns about value, access and quality of education," she tells CNBC Make It over email. "However, that higher ed's target consumers, aged 18 to 29, are more negative for the first time in Gallup's history measuring this topic is particularly concerning."
The United States is considerably behind goals (set by the Obama administration in 2009) to increase the proportion of 25- to 34-year-olds with college degrees or certificates to 60% by 2020, with the hopes of optimizing economic opportunity.
At the current rate, it would take until at least 2056 for the United States to reach that threshold.
Economists and national security experts have also emphasized the importance of training college students in fields such as computer science and artificial intelligence, pointing to projections that estimate AI will add 16%, or $13 trillion, to global economic output by 2030 and suggesting that AI is an issue of national defense.
"Educational failure puts the United States' future economic prosperity, global position and physical safety at risk," reads a report from the Council on Foreign Relations, led by Joel I. Klein, former head of New York City public schools and Condoleezza Rice, former U.S. secretary of state. "The United States will not be able to keep pace — much less lead — globally unless it moves to fix the problems it has allowed to fester for too long."
Overall, women viewed college as more important than men did. This is unsurprising, given research that finds women need to earn one more degree than men in order to earn the same salary.
"A woman with a bachelor's degree earns $61,000 per year on average, roughly equivalent to that of a man with an associate's degree," reads a 2018 report from the Georgetown Center on Education and the Workforce. "The same rule holds true for women with master's degrees compared to men with bachelor's degrees and for each successive level of educational attainment."
The Georgetown CEW found that "women's earnings still lag those of men at every education level, even within the same majors and controlling for full-time, full-year employment."
Black and Hispanic adults were more likely than white adults to say college is very important (65% and 66% versus 44%.)
Just 41% of Republicans said that college was very important, compared to 62% of Democrats and 50% of independents who said the same.
But while attitudes towards college have certainly shifted, and the financial calculation may be steeper than in the past, going to college remains a smart investment for many.
In 2018, college graduates earned weekly wages that were 80% higher than those of high school graduates, according to the Federal Reserve. The Bureau of Labor Statistics reports that Americans with a bachelor's degree have median weekly earnings of $1,173, compared to just $712 a week for those who have a high school diploma.
"Getting a college degree is increasingly important for individuals seeking better employment prospects and greater wages," Michael Mitchell, senior director at the Center on Budget and Policy Priorities tells CNBC Make It. "Indeed, we know that communities benefit when more residents have college degrees. Areas with highly-educated residents attract stronger employers who pay higher wages. And this, in turn, can boost the area's economy so that the wages of all workers at all levels of education are higher."
So why then are Americans increasingly skeptical of higher education?
One likely reason is that college costs have steadily increased over the last several decades (and by more than 25% this decade) due to cuts to education funding, inflation and colleges increasing spending on construction.
During the 1978 - 1979 school year, it cost the modern equivalent of $17,680 per year to attend a private college and $8,250 per year to attend a public college. By the 2008 - 2009 school year those costs had grown to $38,720 at private colleges and $16,460 at public colleges.
Today, those costs are closer to $48,510 and $21,370, respectively. That means costs increased by roughly 25.3% at private colleges and about 29.8% at public colleges.
These increased costs have made students second-guess their calculations about the cost — and value — of college.
"Everyone is asking, 'Is college worth it?'" says CEW director Anthony P. Carnevale.
But analysts stress that earning a college degree remains a strong investment.
"Getting a college degree, if done right, is still the best investment you're ever gonna make," Greg McBride, chief financial analyst at Bankrate tells CNBC Make It. "Even with a modest amount of debt, borrowing $30,000, which is the typical debt of an undergrad, for $1 million in additional lifetime earnings — that's a pretty good return on investment."
Another potential reason students' belief in higher education has been shaken is a current emphasis on college scandals.
Marken says especially that in the wake of the so-called "Varsity Blues" scandal, in which it was revealed that wealthy parents paid roughly $25 million to help their children gain admission to elite colleges and universities like Yale and Stanford, colleges and universities must prove to students that investing their time, effort and money in a college degree is worth it.
"It reminds us that higher education has much to do to communicate the outcomes associated with a higher education degree and its ability to serve students from various backgrounds," she says. That's "a concept many have begun to question in light of the recent college admissions scandal."
Finally, Americans have become enamored by the story of the millionaire, or billionaire, college dropout: people like Facebook founder Mark Zuckerberg and Microsoft co-founder Bill Gates. The two tech titans dropped out of Harvard to found successful companies.
And while Zuckerberg and Gates' success is undeniable, the issue is that they are the exceptions to the rule.
"Although I dropped out of college and got lucky pursuing a career in software, getting a degree is a much surer path to success," said Gates himself in 2015. "College graduates are more likely to find a rewarding job, earn higher income, and even, evidence shows, live healthier lives than if they didn't have degrees. They also bring training and skills into America's work force, helping our economy grow and stay competitive."
One study of 11,745 U.S. leaders (including CEOs, federal judges, politicians, multi-millionaires and billionaires and business leaders) found that 94% of U.S. leaders attended college, and about 50% attended an elite school.
According to the National Center for Education Statistics, just 41% of first-time full-time college students earn a bachelor's degree in four years, and only 59% earn a bachelor's in six years, driving up the cost of attending college significantly.
Even Gates has criticized these dropout statistics.
"This is tragic," he said in a blog post, emphasizing the importance of higher education. "Not just for the students and their families, but for our nation. Without more graduates, our country will face a shortage of skilled workers, and fewer low-income families will get the opportunity to lift themselves out of poverty."
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