FLABBY, OTIOSE, AND even worse, whimsical: labels that might be affixed to an economy increasingly mired in lassitude, beset by the twin problems of inflation and recession. As if those dual difficulties were not sufficient to twist minds from Washington to Cambridge, the latest productivity figures show an alarmingly small rise--indicating that the most jaded and chronic criticisms may in fact be borne out. It's crisis time, and the crescent encompasses a region less foreign than the Near East.

In an effort to subvert dire suspicions of economic collapse, the Republicans have put their best hooves forward on the Senate floor, lurching from tax cut proposal to tax cut proposal. Usurping the populist initiative by adopting a stance historically reserved as a presidential re-election panacea, the GOP in the name of its soon-to-be coronated nominee Ronald Reagan has stolen some traditional Democratic thunder. President Carter last week called the proposal "irresponsible," adding that it would prove the first step in a plan that could cost the Federal Treasury $280 billion a year by 1985.

Against the incumbent's stern, presidential warnings of a tax cut, the Republicans have rushed to fill what they term a "leadership vacuum," and appear anxious to spank Carter in public on the basis of the president's past economic flip-flops. Sen. Robert Dole (R-Kan.), himself a defeated candidate for both president and vice president, spoke out this weekend as the ranking Republican on the finance committee. "Those who are irresponsible in a time of crisis, including economic crisis, are those who cannot and will not act," Dole said in a sharp rejoinder to Carter's accusations of earlier in the week. He added, a touch snidely, that Reagan and the GOP "have filled the leadership void in Washington."

Carter's criticism of the GOP proposal stems from his projection that adoption of the original 10-per-cent, across-the-board individual tax cut plan (businesses would be allowed to deduct new investment on income taxes more quickly) would lead to an eventual three-year 30-per-cent total reduction--a measure supported by many Republicans in the house. The more drastic slash would also adjust rates for inflation annually. Carter himself has said he would review possible tax cut legislation after election heat has subsided, vowing that he would not be tempted by the potential vote-getting power of a reduction in taxes. After all, the call for a tax cut has long been heard from certain senate Republican circles, Dole offering a prime example. And the Kemp-Roth proposal for balancing the budget, which includes a massive tax cut, has been the object of flirtation for many politicos. Martin Feldstein, professor of Economics, has characterized the Kemp-Roth proposal as something "politicians can digest in thirty seconds and discuss for months."

This clamor for a tax cut is probably, to use Carter-speak, "irresponsible." But given the depth of the current slump, and the fact that the economy faces a substantial tax increase next year-- in the form of social security payments, windfall profits payments and the effect of higher tax brackets caused by inflation--it seems reasonable to try the limited tax slash plan recently defeated in the House. As higher production costs and increasing uncertainty continue to stunt incentive in the industrial sector, it may prove necessary to counter the recessionary trend with some sort of tax cut.

Even liberal Sen. Paul E. Tsongas (D-Mass.) suggested last week in a New York Times op-edpiece that tax cuts to businessmen before individuals may be in the best long-term interests of the country. The premise of individual tax cuts--that consumers would use additional disposable income as the savings needed to stem inflation--is a flimsy one at best. External factors such as snowballing oil, food and medical costs point to consumer behavior that entails running as fast as possible to stay in the same place--that is, spending. Republicans respond to such criticism by denying any paternalistic intent, claiming people know what to do with their money.

THE BEST REMEDY for an ailing economy might be a stiff tax on oil--similar to the one extolled by presidential candidate Rep. John B. Anderson (R Ill.) and Harvard Business School professor Daniel Yergin--coupled with a social security tax cut for individuals and investment tax credits for business so that depreciation schedules might be used to better advantage. The gas tax acts as a disincentive to profligate oil consumption, while the additional disposable income afforded by a reduction in the regressive social security tax allows consumers the type of choice that supply-side economists and Republicans say has been slighted by big government. Reaganites, in an attempt to upstage a stumbling president, have inadvertently found themselves championing the cause of the man on the street, the little business on the block.

However specious that claim may seem to students of history, it does not behoove the Democrats in an eelection year to grin and bear stunted growth and unrelenting unemployment. Carter, whose foreign policy pronouncements have left even the most attentive listeners wondering what he really means, has yet to define what he calls "responsible" behavior at home. He should lead by example instead of watching public opinion polls and reflecting the mood of the moment. And though his hesitancy to impose a tax cut marks a departure from his habit of appeasing the pollsters, it's ironic that he may be missing his best opportunity to give the economy a dose of good medicine.