The idea of saving New Yorkers some tax money by charging much higher tuition for out-of- state students in the State University of New York system may seem tempting. But there’s another side to this. With upstate’s population stagnant, maybe New York needs those young out-of-staters at least as much as they need us.

Between 1990 and 2000, upstate New York’s population grew at only one-thirteenth the nation’s growth rate. And since 2000, upstate’s population has actually declined slightly, according to the latest Census estimates, while the nation’s population has grown 7.8 percent. The combined population of Erie and Niagara counties dropped 19,200 between 1990 and 2000. Since 2000, 56,130 people have left Erie and Niagara counties for other states — about 7,000 people a year.

Particularly alarming is what has happened to upstate’s population of young adults — the people who are starting careers, buying houses, having children and putting down roots. Between the 1990 and 2000 Censuses, the 25-to-34 age cohort in upstate dropped by 372,000, or more than 24 percent. Erie and Niagara counties, alone, accounted for almost 50,000 of that drop.

In the absence of strong, dynamic job growth, upstate’s economy seems to be caught in a vicious circle — people leave if there aren’t enough job openings; and then declining population hurts economic growth even more.

What’s all that got to do with SUNY tuition?

Upstate’s best hope for making up its loss of young people may well be the ability of its colleges and universities — both public and independent — to attract students from out of state. These colleges and universities are also our key resource for producing the highly educated work force that a dynamic economy will need.

Those considerations shed a different light on a report issued last month by the Office of the State Comptroller, suggesting that New York could bring in $340 million over four years if it phased in a 65 percent increase in the tuition charged to 16,000 out-of-state students at SUNY.

To hard-pressed taxpayers, of course, $340 million sounds good. But it bears noting that higher education is already one of the few areas in which New York spends less than other states. In fact, according to the Public Policy Institute, New York ranks 46th in per-capita state spending on higher education. And the calculations from the comptroller’s office appear to assume that after the tuition increase there would be no drop in the number of out-of-state students SUNY attracts. Few businesses would believe that a two-thirds price increase wouldn’t result in any loss of sales.

As the State Commission on Higher Education concluded last year, SUNY needs a flexible tuition policy that enables it to reflect the different needs and costs of its campuses. One consideration could be: What might upstate stand to gain if New York encouraged, rather than discouraged, out-of-state students to come here for college? It seems a reasonable hope that if more came, more would stay. They won’t all take off for Boston or Atlanta.

A survey of about 1,000 SUNY graduating seniors conducted by the Business Council of New York State in 2007 found that most liked the idea of spending their adult lives in upstate, or someplace like upstate — a medium-sized city, or its suburbs, in the Northeast. Most even said they enjoyed the four-season weather that upstate offers.

In addition to the demographic potential these young people offer, out-of-staters could be important to the future of New York’s colleges and universities, both public and private, in the years ahead.

Earlier this month, the National Center for Education Statistics forecast that based on school enrollments and other trends, the number of high school graduates coming out of New York’s schools every year will decline for at least the next decade — dropping 11.4 percent by 2019, the seventh- largest decline in the country. That’s a threat to the colleges, to our college communities and potentially to the taxpayers — who might have to shoulder fixed costs without as many tuition- paying students to share the burden.

But the center’s report had a silver lining. Dramatic increases are forecast in the number of graduates pouring out of high schools in states that are already having a hard time growing the capacity of their university systems to keep up with demand. These include Florida (expected to increase 22.7 percent), Virginia (up 17.5 percent), North Carolina (up 33.2 percent) and Georgia (up 41.3 percent).

All those states have significant numbers of expatriate New Yorkers. When their young people face closed doors or overcrowding at their state schools, we ought to have a shot at attracting them to come instead to colleges upstate. If we do, they’ll be an asset for our economy, and our taxpayers.

David Shaffer is a senior fellow at the Rockefeller Institute of Government, a public policy think tank affiliated with the State University of New York.