Call it the (un)affordability paradox.

As tuition seems to rise inexorably, the University of Iowa’s enrollment continues to climb; the cost of college jumps hundreds — sometimes thousands — of dollars a year, and yet students keep coming in droves.

This phenomenon may prompt some to question the significance of the state Board of Regents’ decision this week to increase tuition yet again.

Some may blithely argue that enrollment growth obviates the salience of affordability questions.

The fall 2010 freshman class, after all, was the largest ever; this fall, officials are expecting an even larger influx. In news that seemed to supply even more grist for those skeptical of the students-priced-out-of-college narrative, UI officials told the The Daily Iowan this week they’re considering placing a ceiling on enrollment.

This line of argument is tenable only if one is agnostic about the composition of the student body, however.

If, as a polity, we’re content ensuring all well-off students have the opportunity to matriculate, the rising cost of education may not be distressing.

But if we want to educate students from privileged and disadvantaged backgrounds alike, if we want the UI to be a mélange of different ethnicities and income levels, we should be concerned about the astronomical increase in tuition.

In-state students entering the UI in the fall of 2000 paid what now seems a paltry sum: less than $3,000 in yearly tuition. Last fall’s freshman class — just one decade later — shelled out more than $7,000. (The underlying problem is declining state appropriations, rather than regent callousness.)

It’s hard to argue that staggering spike isn’t prompting some poor and working class kids to second-guess the attainability of a college education.

Public higher education is vitally important both for economic and democratic reasons.

The first is oft-stated: In a global economy, those who don’t have at least a bachelor’s degree are relegating themselves to a future of immiseration. A dynamic, advanced economy requires a well-trained workforce.

While it’s not that simple (automation and outsourcing don’t just hurt the Rust Belt), having a college education certainly helps. You don’t need a bachelor’s degree to avoid privation. But if you want to be relatively well-off financially, you’d better go to college.

In addition, public universities are an inextricable component of vibrant democratic societies. At their best, they provide an edifying environment for students to question societal orthodoxies and develop the critical thinking skills necessary for engaged citizenship.

Professors aren’t there to just impart unassailable knowledge. They should also foster discourse about the vexing problems that confront our society and help students look at them from different perspectives.

In both of these capacities — economic and democratic — universities have a special obligation to assist the impoverished and marginalized: The American Dream is a mere chimera if low- and moderate-income students are shut out of higher education. And a pluralistic, empowering democracy requires not a handful of intelligent citizens, but a preponderance of them.

Instead of further calcifying economic and societal inequality, higher education should be an ameliorative agent. It should extirpate, not perpetuate, inequities.

So don’t be fooled by rising enrollment — the UI has a real problem on its hands.

And state officials are only compounding it when they slash state aid and increase tuition.