The grouse-shooting, which provides a livelihood for many British country folk, was uncommonly good this season. The Observer recently reported, "Parties on moors in the North of England and Scotland have enjoyed higher than average bags."

That pretty much wraps up the good news on the British economic front. Everywhere else you turn -- from double-digit inflation, to mounting unemployment, to an epidemic of bankruptcy, to forbiddingly high interest rates -- the picture is grim and the outlook even grimmer.

It is, accordingly, not hard to understand why Prime Minister Margaret Thatcher is reportedly "ecstatic" about the prospect of Ronald Reagan's presidency. When you consider just how little the Thatcher government's radical, monetarist economic thinking has accomplished in the 19 months since it was overwhelmingly swept into power, you can see why the prime minister is happy to see a kindred soul ready to try somewhat the same radical experiment.

Some part of it has to be a matter of misery looking for company.

The first question you find yourself asking, then, is just how wise is it for Ronald Reagan to keep economic company with Margaret Thatcher's government?How sound a model is the Thatcher experience for what the Reagan economic brain trust has in store for us?

The answer I got from experts here begins with a quick reminder that the American economy is by no means a carbon copy of Britain's, which is obviously smaller, and also less diverse. It is much more concentrated in manufacturing and dependednt on its ability to export at competitive prices. It has its own distinctive labor and productivity problems.

And when Ronald Reagan talks about "getting the government off the backs of the people," he is not talking about denationalizing airlines, steel mills, auto companies, coal mines and railroads. He is not talking about getting the government out of a public housing program that domiciles one out of three families.

That said, there are significant similarities in what ails the two economies: the baffling and crippling combination of raging inflation, high unemployment, slumping industrial production, high interest rates. And there are striking similarities in what Mrs. Thatcher has done about it and what Ronald Reagan says he intends to do about it.

Both favor generous tax-cutting, deep slashing of the government budget, a general freeing up of private enterprise, measures to control borrowing and contain the money supply. All thism together with significant increases in spending for defense.

For Thatcher, it plainly hasn't worked. The budget-cutting has proved a lot more painful and less productive than the government expected. Thus the grip on money control. The prime minister will have to rely on fancy bookkeeping for Britain to meet its promised 3 percent increase in defense spending next year.

Meantime, inflation has soared to more than twice the rate the Thatcher government inherited, reaching a peak of 22 percent a few months ago. It is now declining, and may reach single-digit figures next year. But the cost in unemployment and failing enterprises will continue to be painfully high.

Says London's influential Economist: "Mrs. Thatcher's government is still thrashing around in the shallows of an economic revolution. If it does not now learn to swim fast, it will face a reelection campaign in 1983-84 with Britain's gross national product lower than it was when Mrs. Thatcher took office and with unemployment having doubled in the meantime."

But that's just it. There's still time, some authorities insist, for Thatcher to give her economic experiment a thorough test -- with adjustments and modifications along the way. The conservatives have a 43-vote majority; her Labor Party opposition is nearly prostrate from self-inflicted wounds. Chances of a revolt within her own party are remote; it's down dangerously in the polls. An election now could be suicidal, even for those who might be tempted to challenge Thatcher's leadership.

Not so for Ronald Reagan. The meassage to him from the British experience with Thatcherism is that radical measures may be well worth trying under particular parliamentary circumstances that allow generously for a full test. But if Reagan's own radical treatment for America shows no more results than has Thatcher's for Britain in the first year and a half, his record will be up for wrathful inspection by American voters in the congressional elections of 1982.