This is probably as good a time as any to empty my notebook of a few related misconceptions, each of which perhaps would not warrant its own column, but which together might be treated under the heading of ''false economic realism.''

The hallmark of this sort of argument, common throughout the business press, is the incompatibility of its premises and conclusions. Broadly sensible causes are advanced for wholly nonsensical reasons.

Classics of the genre include the notion that trade barriers are wrong because other countries might retaliate with their own, or that the error in subsidizing certain industries and companies lies in their potential for failure. Neither is true: Our own trade barriers are harmful in themselves, regardless of whether others reciprocate; the success or failure of their recipients has no bearing on the distortion caused by industrial subsidies.

The only effect of such a line of attack is to shift the argument from first principles to empirical observation. If our trade partners did not respond, or if only ''winners'' were subsidized, the implication is that protectionism and pork barreling would be okay. It is then but a short hop to claim that if better leaders were in place - tougher trade negotiators, smarter industrial strategists - these policies could be pursued to advantage.

QUALIFIED FOR THE JOB

And, of course, the very act of making this assertion is persuasive of the speaker's own qualifications for the job. Their opponents, by contrast, having ceded the terms of debate, appear to be confessing weakness.

A couple of examples now in circulation:

Any number of editorialists will explain how the present high interest rates are needed to persuade foreigners to lend to us. Years of big deficits, coupled with falling domestic savings, have made us dependent on foreign capital, and thus at the mercy of international credit markets. Vague reference is usually made at some point to the all-explanatory ''globalization.''

They're right on two points: The deficit is a problem, and we can't just drop interest rates by fiat. But not because we're in hock to foreigners - any more than it is dependence on imported oil that leaves a country prey to international oil prices. It is not imports that impose world prices, but exports. Even if we imported no oil, we would still have to pay the world price, unless we were prepared to impose export controls: otherwise domestic producers would ship their oil abroad.

In the same way, it is the absence of capital controls here at home, not the foreign debt, that demands we pay interest rates set on world markets. Capital isn't perfectly mobile, of course, and it might be argued foreign lenders face more risk and uncertainty due to the volatility of exchange rates. But by and large interest rates in Canada, real or nominal, would not be much different even if we only borrowed from ourselves.

Another key effect of the deficit, according to received wisdom, is to ''constrain fiscal policy.'' In former times, supposedly, governments would deliberately increase the deficit, either by raising spending or cutting taxes, to pump the economy out of recession. But with the deficit and the debt having grown so large, this is no longer possible.

(Of course, we are also not supposed to cut the deficit, or at least not now, since that would deepen the recession - though at what stage of the business cycle it would be permissible to take such a contractionary measure is an open question: If in the first stages of expansion, the cry would surely go up not to ''jeopardize the recovery,'' and if in the latter stages, not to ''kill off prosperity.'' The deficit, it seems, like the dollar, should always be exactly wherever it is.)

Aside from the historical revisionism on display - no government in Canada has ever successfully engaged in this kind of fiscal fine tuning - the thing I like best about this argument is its glorious internal contradiction: If deficit spending had such effect on the economy, why would we need more of it now? Fisal policy has been massively stimulatory for years. The recession from which deficits might theoretically rescue us - but for the deficit - should not have been possible in the first place.

This attempt to argue for fiscal conservatism from fiscally liberal premises lacks even the courage of its Keynesian convictions. If deficits are stimulative, then the deficit should not be a concern: The economy grows, tax revenues rise, social spending drops, the deficit contracts. It'll pay for itself. You can file that one under ''discredited economic delusion.''