AT A TIME when government budgets are being examined with microscopic intensity, few seem to be noticing a remarkable trend that would take power over many local budgets away from government officials and put it in the hands of unaccountable outsiders.

The trend is toward adoption of compulsory binding arbitration laws, which have now been passed with astonishingly little attention by 18 states. A move is now afoot in the Marylnad legisature to add Maryland to the list.

Labor costs constitute, on the average, about 70 to 80 percent of most local operating budgets. In school budgets, personnel costs are an even larger proportion -- 90 to 95 percent.

Thus when public employe contract negotiations reach an impasse and such steps as labor mediation and fact-finding fail -- as is increasingly likely in painful economic times for both governments and workers -- those with final and absolute say over contracts control local budget decisions.

In Michigan, for example, where binding arbitration is mandated for police and firemen, one mayor was forced to lay off many trash collectors to finance a firefighter pay raise, and another mayor laid off many needed policemen to finance arbitrator-ordered pay raises for the remaining police.

In other words, while Proposition 13 fever is universally seen as reflecting taxpayer demands for more budget control, taxpayers in many states are actually relinquishing their control, and the pressures to expand this trend are growing. An Alternative

EARLIER THIS month, the Prince Georges delegation to the Maryland General Assembly endorsed a proposal to give the county's blue-collar school employes the right to compulsory binding arbitration. It may also back a similar plan for county teachers. If that were not enough, the blue-collar bill embraced the "final offer" variety of arbitration, under which the arbitrator must pick either the union or government offer on each item and nothing in between.

It is not hard to imagine what might happen if it passes. Assume that the union is seeking a 12 percent increase and the school board, under a stern mandate from the county council, is offering 2 percent. The union, knowing that it can probably do better with an outside arbitrator (who doesn't have to face an indignant electorate) than with public officials (who do), stands pat and forces the issue to arbitration. If the arbitrator takes the 12 percent package as the "most reasonable," the school board has to pay it. If that requires higher taxes or throwing other public workers out of their jobs, those prices, too, have to be met.

Compulsory binding arbitration, no matter how you package it, undercuts both representative democracy and the collective bargaining process.

As former Prince George County Executive Winfield M. Kelly Jr. said when such arbitration was proposed last year during a police slowdown, "I will not put this county's financial matters in the hands of outsiders. We are determined to keep the tax rate down both now and in the future." His successor, Lawrence J. Hogan, promised binding arbitration to police during his campaign but now has indicated opposition to the school bill.

Public employe advocates of binding arbitration argue, "If you don't want to give us the right to strike, then there should be arbitration." But there is a third alternative, particularly appropriate in a time of taxpayer concern over budgets -- the referendum.

In Englewood, Colo., a union can remendations, on its own last best offer or on the city's last offer. The one winning the most votes prevails. In the 6-year experience, there have been only three impasses, and all were resolved without an actual vote. Faced with a referendum, both sides ended up accepting the fact-finder's recommendations. In 1977, two more Colorado cities adopted similar ordinances.

If the Maryland legislature will take a 16-month-old report by its own Task Force on Collective Bargaining for Public Employes off the shelf, it will find on page 40:

"As to the final decision on contract terms, the task force by a large margin rejected compulsory binding arbitration of fiscal matters. The task force found it unacceptable to turn over to an outside third party the important questions of budget and tax policy which are involved. In the public sector elected representatives should continue to make ultimate decisions."

It is good advice.