Whenever someone insists we send too many high school graduates on to college, I resist the urge to say, “Let’s start with your kids and see how that goes.”

Yes, everyone knows about the successful CEOs and innovators without college degrees — Steve Jobs, Bill Gates and Mark Zuckerberg. But many more Americans without degrees are struggling and facing futures without the possibility of a tech start-up that will turn them into billionaires.

The soaring cost of college combined with the weak job market for newly minted graduates has prompted a reconsideration of the value of a degree. While a college degree may not matter to those gifted with world-class genius, it makes a difference for the rest of us. We ought to ensure young people understand a college degree remains a good investment that pays out in a lifetime of higher earnings.

In fact, the wage differential between college and high school graduates is higher than ever. Between 1979 and 2012, the gap in annual earnings between a median college-educated two-income household and a median high school-educated two-income one jumped by $28,000.

Writing in the journal Science earlier this year, MIT economist David Autor said inflation-adjusted, full-time earnings of college-educated males increased from 20 percent to 56 percent between 1980 and 2012, depending on whether they also acquired graduate degrees. During that same period, real earnings of high school graduates fell 11 percent, and earnings of high school dropouts fell 22 percent.

A panel at Spelman College last week discussed the worth of a college diploma in light of skyrocketing tuition costs. The discussion followed a screening of the new documentary “Ivory Tower,” which premieres on CNN at 9 p.m. Thursday. The ambitious film tackles all the big questions: college access, affordability and relevance. (I’m not sure it answers any of them, but it’s fast-paced and interesting.)

Panelist Brian K. Bridges, a United Negro College Fund vice president, told the audience of mostly Spelman women, “Don’t get into your mind that college isn’t worth it. The vast majority of people, on average, earn more than twice what someone with a high school diploma earns. Yes, in the last recession, college students had a hard time getting a job, but not as hard a time as people without a degree.”

The panelists agreed the price of college was hurting low-income students, and that higher education had to rein in costs or risk becoming a system affordable only to the affluent.

“The cost of college is unsustainable,” said Bridges. “It has increased more than a thousand percent in the last 34 years. If that continues, college will become the province of only the most wealthy in the country.”

Before the recession, Georgia State University students graduated $13,000 in debt on average, said Timothy Renick, vice president for enrollment management. Now, it’s $20,000.

As with many public colleges, GSU endured crippling cuts in state funding. In 1967, GSU’s share of revenue coming from state support was 67 percent; today, it’s 35.2 percent. That has prompted new efforts to contain costs, including examining courses at the time of registration to see if GSU students were enrolled in the right classes for their programs. The latest review led to 2,000 instances of students moving from courses that didn’t fit, said Renick.

Colleges are “squirming” under growing concerns about their missions and their methods, said panelist Goldie Blumenstyk, a senior writer for the Chronicle of Higher Education and author of “American Higher Education In Crisis?” That squirming may be why College Board data released Thursday showed the trend of rising college sticker prices was slowing.

“All colleges have to pay attention and rethink how they operate at every level,” she said. “This is really about their reinvention, but the question we ask at the Chronicle is, reinvention for whom?”