Pretend you're President. A growling political menace of an issue has just landed on your desk. You don't want to touch it, but the country is clamoring that it be tamed. What do you do?
When in doubt, you can always appoint a commission.
Ronald Reagan, during his term in office, has made effective use of this time-honored presidential tactic.
* The National Commission on Social Security Reform, ''a nearly perfect example of commissionship,'' in the words of one Washington political scientist, may have defused the hot issue of social security.
* The President's Commission on Strategic Forces, formed by Mr. Reagan in a quick side-shuffle in December, helped prevent a showdown between Congress and the White House over the problem of where to put the MX missile.
* Less-publicized panels, such as the President's Task Force on Victims of Crime, have allowed the Reagan administration to show action on issues dear to the hearts of conservative supporters.
Though it's difficult to determine an exact figure, since there are many types of citizen groups that advise the executive branch, President Reagan has appointed around a dozen full-blown presidential advisory commissions, on subjects ranging from drunken driving to United States radio broadcasts aimed at Cuba. The newest panel, created on Jan. 14, is the Presidential Commission on Indian Reservation Economics, appointed for the Reaganesque purpose of promoting private sector development on Indian lands.
Jimmy Carter, when President, appointed commissions at about the same rate as Reagan. Presidents Johnson and Nixon named them relatively faster, political scientists say.
Presidential use of these civilian advisory groups was apparently inspired by the British, whose royal commissions have been dispensing well-mannered advice for hundreds of years. Their use in the United States dates back to 1794, when George Washington appointed a commission to investigate ''The Whiskey Rebellion, '' an up rising of Pennsylvania distillers angered by federal liquor taxes.
But commissions didn't become a normal tool of government in the US until the early 20th century, when a string of influential panels changed the face of American government, says Frank Popper, author of a 20th Century Fund study on presidential commissions. Between 1900 and 1945, commissions led to the formation of the Federal Reserve Board, the federal budget, and the modern, heavily staffed Office of the President.
After World War II, presidents increasingly appointed commissions in response to specific events. President -Kennedy's assassination, the inner-city riots of 1967, and the Three Mile Island nuclear power plant accident were all investigated by the sort of panel invariably described as ''blue ribbon.''
Do these commissions provide valuable advice? Or are they elaborately produced charades, designed to give the appearance of action?
As a general rule, writes sociologist Nathan Glaser, commissions tend to sweep up ideas that already exist and give them an aura of respectability.
Then, political scientists say, the impact of the panel's report is often inversely proportional to the size of the problem it addresses. The sweeping ''social'' panels of the Johnson and Nixon years, such as the '70 Commission on Campus Unrest, produced lots of headlines and little legislation.
On the other hand, ''there are lots of little commissions you and I never heard of, that anticipate problems and operate in obscurity,'' says Martha Derthick, a Brookings Institution fellow who served on the campus-unrest panel.
A 1964 commission, for instance, successfully reorganized federal health-care research priorities. The final report of the President's Task Force on Victims of Crime, released Jan. 27, suggests specific ways for making the legal system more responsive to the rights of victims.
And even if a commission's suggestions aren't speedily adopted, the mere fact that a group of eminent citizens is furrowing their brows over a particular problem makes the country take that problem more seriously.
''They legitimate these things,'' says Mr. Popper, a fellow at Resources for the Future.
The National Commission on Social Security Reform, if nothing else, has already riveted the nation's attention on the need for social security reform. Its suggestions stand a good chance of passing Congress, and it appears to have protected both Congress and the White House from the politically explosive issue - a nearly faultless example of adroit commissionship on the part of President Reagan.
It will be difficult for the Commission on Strategic Forces to be so successful. Most commissions are hobbled by lack of time, but the CSF has until only Feb. 18 to solve a particularly tough riddle: What should we do with the MX missile?