THE FREE LUNCH lives again--if you believe the tax breaks proposed by D.C. Council Member John Wilson for residential property owners. Mr. Wilson, who sort of seeks higher office every once in a while, has a special discount for the 1982 political season: reductions of up to 18 percent in residential property tax bills, along with a six percent cut for commercial property, a 50 percent tax break for cial businesses to encourage the hiring of D.C. residents.

There may be one slight problem with all these charitable proposals--the matter of what the city will use to pay its bills. Tax officials suggest that Mr. Wilson's reductions would have cost the city $20 million had they been in effect this year, and would cost substantially more next year, when he would like to see the changes go into effect. Add to his earlier proposal to cut the business franchise tax, and there's another $20 million that would be missing.

So what would Mr. Wilson do about the lost revenue and the effect on city services? He replied the other day that he didn't know how much his proposals might cost the city in lost revenues and--get this--had not tried to find out because running the city is not the responsibility of the council. "I wasn't interested," he said, adding that the obligation of the mayor "is to run the city with whatever revenues the legislature levies."

Well, that's separation of powers for you--and if Mr. Wilson ever were to wind up in the mayor's chair, presumably he would fulfill his self-imposed obligation to make do with whatever allowance a council might fork out. But as you can conclude about his program itself, no one should count on it.