In confirming State Tax Commissioner Roger O. Tew to another term in office this week, the Legislature did the right thing. Much criticism had been leveled against Tew for failing to correctly forecast state revenues. Utah ended up this fiscal year with a hefty surplus. But it would be unfair to punish an official for not being able to see into the future.

In recent years, Utah had been hurt by several revenue shortfalls as a stagnant economy failed to produce the amount of income the state expected. That led to painful cuts in state agency budgets and put the Legislature in a difficult position.The Deseret News suggested last year that the state would be better off if it took a more pessimistic view of anticipated revenue. Such an approach would be less likely to leave the state scrambling to cover shortfalls.

State financial experts apparently agreed with that approach. Not only Tew, but the Legislature's own budget analysts, took a conservative approach and came up with similar figures.

But after several years in the doldrums, the Utah economy began to make an unexpected comeback. In addition, the tax picture was complicated by changes in both the federal and state income tax laws.

The upshot of all this was that the state finished the 1987-88 fiscal year with a surplus of more than $100 million, necessitating a tax rebate in the midst of a tax revolt - an embarrassment of riches, as it were. And Tew became a target of criticism.

If being unable to forecast the future during a time of economic uncertainty were to disqualify state officials, it would be a rare person indeed who could hold public office.