MAYOR BARRY is right to make a hiring freeze the District's first step in dealing with its financial crisis. But the District government must manage the freeze properly to make it more than an empty gesture and one that can harm the quality of city services by leaving key jobs vacant while not saving the city very much money.

There is some history here that repays study. Two previous District government hiring freezes (which each saved the city about $16 million, according to the city budget office) were not handled well. The main problem with these efforts in the mid-'70s was that District officials did not enumerate the jobs they considered essential. As a result, a hodgepodge of jobs was affected, some important, some unimportant. Generally, they were relatively low-level positions, such as janitors, cooks and jail guards -- jobs involving front-line service to citizens.

These jobs were so quickly affected because there are more of them than there are high-paying administrative jobs, and the strain of working as a jail guard or caring for abused children makes for a higher turnover rate, leaving more positions vacant during a freeze. The result was that some services were decimated while other were left untouched. Another problem was the absence of a single system in the government for classifying employees: one department might call an aide to an administrator a secretary and freeze the position if it was left open, while another might call the holder of the same job an administrative assistant and fill the vacancy. Also, during the last freeze some city agencies wound up paying large amounts of overtime to make up for staff shortages. Money saved by the freeze went to pay for overtime. That makes no sense.

Bladys Mack, the city's budget director, who is to be in charge of this newest hiring freeze, says it will be based on the principle of limiting every agency's number of employees. When the number of agency employees falls below its limit, then the agency will again be able to hire employees -- until it gets back to its limit. There is no freeze on job positions important to public health or safety, Mrs. Mack said. But besides policemen and firemen, what jobs fit those categories? She says that individual agencies will decide.

A list of jobs the city finds essential must be drawn up. If any of the "essential" jobs is vacated during a hiring reeze, then, when possible, a worker in a nonessential position should be moved into it. There is one other prerequisite: the mayor needs to keep close track of money saved by the freeze.