What do you do when the family comes into a modest amount of one-time money? Maybe you finally get the roof fixed or remodel the kitchen. Or perhaps you set aside some of the windfall as savings against a rainy day. Perhaps you even pay off some existing debts. If you’re prudent, the one thing you probably don’t do is put money down on a new purchase if you can’t afford the monthly payments.

“One-time windfall” describes the situation that the legislature will find itself in when it convenes for the biennial budget session in Olympia. Revenue has been coming in faster than expected. Current forecasts are that the general fund will end the biennium with a billion-dollar surplus. The revenue forecast for the coming biennium predicts adding another $2 billion on top of the current surplus.

The projected billion-dollar surplus from this biennium covers about one month of state spending. Together with the expected increase in revenue in the coming biennium, the state can undertake a few small new initiatives and also provide the funds needed to cover increases in the cost of living over the last two years.

All this is good news, but it mostly reflects the upswing in the business cycle rather than a permanent revenue increase. Wise leadership would act like a family that’s won a few months’ income from Lotto or from a small inheritance. It would be shortsighted to  adopt a grandiose life style when you haven’t gotten a permanent raise.

This family windfall metaphor isn’t perfect because the money the legislature spends isn’t theirs, it’s our money—the taxpayers’ money. So the extra question that must be answered is whether state projects are more worthwhile than some projects most of us have waiting to be done around the house. In other words, why not rebate the money to the taxpayer?

I’ve been on plenty of jammed highways lately. I work in a state building that’s going to fall over in the next big earthquake. My answer is that, much as I’d like to get some tax money back in my own pocket, I can see lots of work the state ought to be doing.

What I can’t see is ramping up permanent state spending to match what looks like a temporary revenue surge.

There’s a deep—if completely obvious—economic principle here: Don’t commit to future spending that you can’t afford.

Since some part of the economic growth will persist, we can afford a few new programs or some expansion of existing ones. The prisons are busting at the seams and we have little kids with no health insurance. But moderation is needed to avoid creating a permanent spending bow wave that’ll swamp future budgets.

Spend some extra money fixing our roads or bridges. Speed up some of the deferred maintenance on state property. Even better than not adding to permanent spending, some extra fix-ups now mean we can get ahead on construction-and-maintenance costs. We’ll be ahead of the game, if revenues turn down in a couple of years.

I am personally in somewhat the same position as the state. My roof, which has been springing an occasional leak, really ought to be completely replaced sometime in the next few years. Fortunately, I’ve got the money to do the job right now and I have a first-rate roofer. I’ve told the roofer to replace my roof now, even though it might be a year or two early. This way I won’t have to cover the expense next year or the year after.

An important part of the story is having a roofer I trust. I’m not spending money just because I have it. I know I’ll get good value. The state, too, should be sure it’s getting good value on projects it picks.

For the most part a fiscally responsible government—just like a sensible family—uses one-time money for one-time expenditures. This one time, that’s what Olympia should do.