All fall we've been criticizing an initiative -- later thrown out by the courts for signature-gathering irregularities -- that would have imposed a state spending cap. So last week Gov. Brian Schweitzer revealed his proposed budget that includes ... a spending cap. What's the difference?

As it turns out, all the difference in the world.

The initiative's cap, based on cost-of-living and population figures, would have been like those painfully small shoes that Japanese girls used to be forced to wear in order to keep their feet fashionably small: a senseless, artificial constriction driven not by human needs, but by a harsh and heedless ideology.

The governor's proposal, on the other hand, would set a spending cap beyond the point where reasonable public-service requirements are met, and would place expected revenue beyond that amount into a rainy-day fund. The "Big Sky savings account" would be used when Montana's currently booming economy inevitably returns to the low end of the cycle.

Of course, exactly at what point such a cap should kick in is a matter of debate, and you can bet it will be debated at length in the next Legislature. Still, the concept of a general-purpose rainy-day fund makes excellent sense.

Schweitzer's budget, rainy-day fund and all, pretty much contains something for everybody. It can do so precisely because the state's booming economy, led by robust oil and gas exploration, is expected to produce a nearly $1 billion surplus.

The governor's proposal includes significant increases for public education, including one-time money for school construction, and enough additional cash to freeze university system tuition. It bolsters funds for mental health care and public safety, provides for a base state-employee salary increase of 3 percent, chips away at projected retirement-system shortfalls, and includes $100 million in property-tax rebates and additional tax cuts for small businesses.

Obviously there will be disagreements about the dollar amounts involved.

And don't forget that the Republicans have their own proposals, only some of which resemble the governor's. The state's closely divided Legislature guarantees that compromises will be necessary.

But the good news for all sides is that compromising on how to slice up the state's revenue pie is a lot easier when the pie is so big.