THE EFFECTIVENESS of the new administration's efforts to control inflation and stimulate economic growth may depend in large part on how much the relevant parties -- business, labor, Congress and the consumer -- think that, this time, the people in charge really mean business. For this reason, the symbolic value of Mr. Reagan's freeze on federal hiring should not be dismissed.

Like all symbols, however, this one has its costs. If these are allowed to mount too high, the value of the gestrue may be lost in the subsequent squabbling. Most of the numerous personnel hiring restrictions imposed in recent years have been made retroactive to cover job offers made in anticipation of the freeze. Unlike other freezes, however, the retroactive period for this one is very long, going back to Nov. 5.

There are some things that the administration might consider to reduce the individual hardship caused by this action and the loss of governmental efficiency it will entail. One would be to move thee retroactive period up to the first of the year. Most of the bad-faith job offers -- the ones that the lame-duck agency heads made to preempt their successors -- apparently went out in January. Relatively few offers for positions not already filled were made in November and December and most of those were the result of time-consuming personnel processes begun long before the election. This step alone would eliminate most of the real hardship cases that are likely to involve agencies, OMB and the court system in endless haggling.

A second step would be to streamline the appeals process for hardship cases so that agencies can dispose of appeals, subject to strict guidelines, without the months of delay required for review by OMB. Mr. Stockman and his aides have more important things to do.

One question about the freeze is how you get out of it as, inevitably, an administrator must. We would suggest an early spring thaw. Across-the-board freezes are a very bad way of managing personnel reductions. No private employer with any concern for efficiency would consider their use. Cuts imposed through freezes may hit hardest on the most important programs and services. Since the most able employees also tend to be the most mobile, overall staff quality deteriorates. Turnover is concentrated among the lower personnel levels, so a top-heavy work-force quickly develops. The practical necessity of numerous exceptions to cover critical functions will quickly become obvious and the number of exemptions sought, and the difficulty of handling them in a fair and efficient manner, will mount. All of this is particularly true after the long and continuous period of partial freeze imposed by the Carter administration almost a year ago.

The federal workforce has not grown in size for a decade. Federal functions have increased enormously.If we are to have fewer bureaucrats, then decisions must be made to have the government do fewer things. An undermanned, haphazardly staffed bureaucracy cannot provide efficient government.