As unemployment mounts toward what the administration now admits may be a 10 percent rate, it is more clear than ever that a depressed economy is the Reagan cure for inflation.

"After all the rhetoric of 1981," Nobel prize- winner James Tobin told the Joint Economic Committee of Congress the other day, "the federal government's anti-inflation program is the same as Mrs. Thatcher's in England, the same old remedy that previous administrations have intermittently tried."

The frightening thing is that almost all economists agree that "recovery" from recession this year will be modest, not enough to make a real dent in unemployment. As Tobin notes, each recovery from recession in recent years has ended with the unemployment rate higher than it was in the last cycle.

The administration, of course, brags about its success in bringing down inflation. What no one in the Reagan circle likes to confess is that reduced price pressures are the product of obscenely high interest rates (which have depressed the economy and produced high unemployment) plus lower international oil prices and a good break on food prices.

You may wonder whether the liberal Tobin is overdrawing the comparison with Prime Minister Margaret Thatcher in Great Britain. Listen, then, to what economist Rudolph Penner, resident scholar at the conservative American Enterprise Institute, said in a piece headlined "We Could Fall Farther Than Britain" in last Sunday's New York Times:

"Can a recovery start in the face of today's interest rates or will President Reagan soon be Thatcherized? . . . (The economy) will (recover) some day because the growing pent-up demand for houses, autos and business capital will eventually be able to overcome very high interest rates.

"But unemployment could reach British levels (now 12 percent) before that happens, and if interest rates should continue to rise, there is a growing danger of a cumulative downturn." (Ominously, interest rates have turned up sharply again.)

If Congress fails to change Reagan's "religious commitment" to his administration's "full defense program and to the third year of its personal tax cut," Penner concludes, "watch out, Mrs. Thatcher. We may show you a thing or two about how to really depress an economy."

What conservatives like Penner and liberals like Tobin have been arguing for is a different mix of policies (not necessarily the same precise recipe) that would tighten up on fiscal policy, so as to take some of the burden off a monetary policy that creates record high interest rates.

This conservative strategy has been pressed by Rep. Henry Reuss (D-Wis.) and will be the basis of a report Reuss's Joint Economic Committee issues on Feb. 25. A similar theme was explored at the Wye Plantation in Maryland last weekend at a Democratic powwow attended by former Vice President Walter Mondale, House Budget Committee Chairman James Jones (D-Okla.), and a handful of liberal Democratic economists.

But Democratic politicians are far from united on how to proceed. Mondale--who has the presidential bug--promptly endorsed the idea of postponing the 1983 tax cut in exchange for easing up of Federal Reserve policy. But Jones, who is trying to hold conservative House Democrats in line, is more cautious.

At lunch with Washington Post editors immediately following the Wye conference, Jones made clear he is still mindful of Ronald Reagan's commanding personal appeal to the electorate, and unwilling to lead such a challenge to the president.

Despite a "real depression" in the nation's agricultural belt and rising unemployment in the Midwest manufacturing states, Jones cautioned that "there is such a hunger for leadership" that these same affected citizens "don't want to tear (Reagan) apart." The basic economic goals of the Reagan administration "are supported by the vast majority of the people," he added.

The Jones approach would allow precious few Democratic initiatives this session. That third stage of the tax cut, says Jones, can be dropped only if the president makes the proposal. "He's responsible for charting the course," Jones said. "He has the first responsibility. The way we look at it, if it's something we can support, we will."

Realistically, the only way a challenge to the Reagan program can develop, Jones says, is "if financial markets deteriorate. Then, I can see a bipartisan program" originating in the Congress to do some of the things suggested at the Wye conference.

This approach is much too timid. The Wye proposals, and those coming up in the Joint Economic Committee's report, are quite modest and need the support of Speaker Thomas P. O'Neill and other House leaders. There must be a better way of avoiding Thatcherization of the American economy than to come right to the edge of disaster. Surely, the Democratic party can afford to be as radical as the AEI's Penner.