Terry Howell, seeker of off-campus housing for University of Hawai'i students, picks up the phone and frequently gets up-close and personal with a part of human nature we'd rather not acknowledge too often.

Greed.

"I've had someone call to say they'd rent a room in their house for $1,000," Howell said. "Once I even said to the person, 'You're kidding me, right?' They said, 'Someone will pay it.' "

Someone will pay, of course, which is why someone else might charge the next student a grand to hole up in their bedroom. There are even people willing to pay, Howell said, for the privilege of crashing on someone's living-room sofa every night.

On an island with this kind of housing supply and demand, rents will surely keep spiraling upward. The ceiling is nowhere in sight. And that's enough to make an old environmentalist (not to mention an old cockeyed optimist) hit the roof, because the only recourse lies in building more homes on our crowded island.

It's finally becoming clear that there is no demand-side solution to the critical shortage of affordable housing, and those suffering most are the ones with the fewest options: renters. Many erstwhile landlords are trying to cash out while real estate prices are still sky-high, and the ones who are left seemingly can charge what they like.

This time, the ones who are inflating the "bubble" are not Japan's speculative investors of the '80s, investors who later pulled up stakes and let prices sink once more.

On the Neighbor Islands, many may be well-heeled newcomers hoping to carve out a bit of paradise, but here on O'ahu it seems that buyers come from the middle class, trying to grab a small squib of property before it all rockets out of reach. The message to struggling first-time home buyers and renters is: We have met the enemy, and it is us.

Will there be any fewer home-hunting competitors out there? Not likely. If anything, O'ahu will soon see more military renters joining the fray, armed with generous housing allowances.

Wai'anae resident Ronald Young wrote The Advertiser a letter, suggesting, among other ideas, that the military be compelled to house its unmarried personnel entirely on base.

That might ease some pressure. But it's doubtful that there's the political will to compel such restrictions. Pretty soon, the cadres of single military renters, pooling their government subsidies, will be the only ones able to afford the high cost. If these folks are shut out of the game, landlords are sure to squawk.

So we turn to supply-side economics, a concept that we liberals love to hate. We swallow hard and choke out these words: We've got to convince developers it's profitable business to produce homes for sale or rent at a decent price point. Unless we want to pave paradise from shoreline to shoreline, we've got to do it largely through an increasingly dense urban core.

Put another way: We've got to build up. And up. High-rises with, perhaps, smaller and more affordable units on the lower floors.

Naturally, all this should have dawned on us years ago.

Some people actually did think about it, but elected officials empowered to do something just sat back. Rick Cassiday, a real-estate consultant, saw this affordable- housing catastrophe coming a mile off. But good planning never seems to be part of government reality.

"The body politic," he observed wryly, "does not act fast."

That's a rant for another day. Fact is, here we sit, in a fairly desperate situation that will get worse before it gets better.

We can hope that renters might find the "mom-and-pop" landlords who aren't pocketing windfall profits off their tenants, simply because they can.

It might be possible to believe that, except that this newspaper has run a few stories about hard-luck cases. Judging by the phone calls our reporters fielded from landlords ready to pounce, generous souls are truly part of an endangered species.

And so are those who don't perceive the mess we're in.

Surely they're living in another realm. They're not renting a sofa in someone's living room, in any case.