Last Monday I was on a media panel at the annual meeting of the Council of Independent Colleges' 2015 Presidents Institute, a gathering of the heads of independent liberal arts colleges. Our topic for discussion was college affordability and student loans.

My perspective is that the core issue with college affordability is a lack of income growth for a majority of U.S. households. An emphasis on the income side of the college affordability ledger means the worry about paying for college isn't going away.

In the short run, private sector payrolls are up for 58 straight months. (Employment growth has been held down by cuts in the public sector workforce.) Still, it's doubtful many workers will feel comfortable enough about the economy this year to march into the boss' office and demand a 5 percent or 10 percent raise or else they'll walk. Odds are the most likely response will be, "We'll miss you."

The long-term household income story is even more important. Whether measured in wages, earnings or total compensation, the inflation-adjusted pay narrative remains the same: Workers have seen their pay go up a modest amount over the past three decades — with an exception of the 1995 to 2000 time frame, when real incomes rose smartly. Meanwhile, for a variety of reasons the cost of attending college has gone up significantly.

For example, median family income rose by slightly more than 15 percent from the 1983-84 school year to the 2012-13 school year, according to the Economic Policy Institute. Over the same time period, the cost to attend a four-year public university increased by 126 percent and for private college 129 percent. To pay the bill students have taken out large loans. The average amount of student loan debt is some $25,000 and the median about $14,000. These debts are a burden to newly minted college graduates struggling to launch their careers.

To be sure, college is one of the best investments most people can make. Despite the high cost of college and the weak labor market of the recent past, the average return of a bachelor's degree is about 15 percent, according to calculations by economists at the Federal Reserve Bank of New York. That's more than double the average annual return to stock market investments since 1950 and five times the return to bonds.

Thing is, 15 percent is an average. Individual returns among college graduates vary significantly, depending on the degree earned, the amount borrowed, the timing of graduation, and so on. Young workers also lose or leave their jobs a lot. From January 1990 to mid-2014 the monthly unemployment rate (seasonally adjusted) for ages 20 to 24 averaged 10 percent, according to Robert Arnott and Lillian Wu of Research Affiliates. In sharp contrast, workers 45 and older had an average unemployment rate of 4 percent. There is a lot of risk attached to a college sheepskin.

What is the personal finance takeaway? First, a college education pays. Second, everyone needs to be wary of debt. Borrow as little as possible. How much you will need to borrow should enter into the decision of where to attend college. Avoid so-called private student loans. They're nothing more than an inflexible consumer installment loan with a misleading label. And get that college sheepskin on time, hastening the day you can start turning a degree into a career.

Chris Farrell is economics editor for "Marketplace Money." His e-mail address is