It's as if you tried to stop a speeding car by sticking your hand out the window, to increase wind resistance.
Way in the back of the Reagan budget is a section on controlling federal demand for credit. Much is made of small cuts such as reductions in Export-Import Bank loans; little is said of increased borrowing to finance the federal deficit.
''I find that a bit amusing; ironic, as well,'' says Rudolph Penner, an American Enterprise Institute economist. As Dr. Penner points out, reining in the deficit is the only way to really put the brakes on government's need for credit.
Washington's growing demand for money has made it ''the dominant consumer of the nation's financial resources,'' the budget claims. From 1955 to '59, the federal government absorbed an average of 18 percent of domestic credit. By 1981 , according to the budget, Washington was gobbling up 35 percent of the $407.8 billion raised in US credit markets.
Federal credit demand has long been the conservative economist's version of Dracula. As this year's budget says, ''Unprecedented federal credit demands reduce the nation's ability to improve productivity and output. Increasing demand for credit by the government and the borrowers it serves saps the vitality of credit markets and hampers their performance. . . .''
The budget makes these specific points:
* Private borrowers get ''crowded out'' of credit markets, because the federal government, in effect, elbows its way to the front of the line.
* Since they're insulated from the reality of risk, federally assisted borrowers (those with Small Business Administration loans, for instance) tend to be less productive than borrowers with more on the line.
* Interest rates get an upward shove. With Washington snatching so much of the credit supply, private borrowers must bid higher for a slice of what remains.
''Unless the burden of federal and federally assisted borrowing is curtailed during the 1980s,'' the budget concludes, ''prospects for permanent monetary control and inflation reduction will be substantially lessened.''
Unless the deficit is brought under control, curtailing federal borrowing will be very difficult.
In 1981, funds raised under federal auspices amounted to $142.1 billion. Of that total, guaranteed loans - private loans Washington guarantees will be paid back - accounted for $28 billion. Borrowing by government-sponsored enterprises - quasi-public institutions such as the Federal National Mortgage Association - accounted for $34.8 billion.
But 56 percent of Washington's borrowing, $79.3 billion, went to defray the federal deficit.
Though the figure isn't exactly comparable, the fiscal year '82 deficit is now estimated at $98 billion. Clearly, there is an upward trend in the component of federal credit demand used to finance the deficit.
The budget's chapter on controlling federal credit, however, focuses on attempts to slash guaranteed loans and borrowing by government-sponsored enterprises. The administration proposes cutting such activities by $21 billion.
Among other efforts, Small Business Administration direct loans would be eliminated. Government National Mortgage Association loan commitments would be slashed $9.6 billion. Export-Import Bank direct lending would go down $0.6 billion, and the Farmers Home Administration would lose $2.6 billion in direct loans and $0.6 billion in loan guarantees.
International Security Assistance loans, on the other hand, would increase $1 billion. Public-housing guaranteed loan commitments would also rise.
''Federal demands on the nation's financial markets will be substantially alleviated in the years ahead despite temporarily higher federal borrowing to finance the deficit,'' the budget says.
Such a statement is not surprising; federal budgets tend to be sanguine about the economic future. They are partly political documents, after all.
Many economists, however, think federal credit demand will just keep racing away over the horizon. ''I'm more alarmed than the administration seems to be,'' says Dr. Penner.
In fact, he thinks the administration may have underestimated the government's share of domestic credit markets. Washington gobbles up ''well over half'' of the US credit pool, he says.
An economist who asked not to be named was more in the middle. ''Under the deficit targets they've set,'' he says, crowding-out might not occur.
''Within a $100 billion (deficit) is something we can live with,'' the economist says. And a recent Citibank economic forecast estimates that crowding-out won't get worse if the '83 deficit doesn't go over $93 billion.
But total government credit demand, including off-budget outlays, is already estimated at $107 billion in '83. A glitch in the economy could send the figure soaring - each percentage point added to the unemployment rate costs the government $25 billion, for instance.
''You'll have a hard time finding economists who would not be worried about the kind of deficits we're going to experience over the next few years,'' says Penner.