WHILE THE LONG SLIDE in stock prices halted yesterday, immense turbulence continues in the markets. In the aftermath of the first shock, both the administration and Congress are trying to collect themselves and decide what to do.

The basic cause of this collapse is anxiety over the prospect of rising inflation and interest rates, both of which are bad for stock prices. The anxiety is being generated chiefly by the gigantic American budget deficit and the trade deficit that is closely linked to it. Throughout this year, people in the stock markets have come increasingly to realize that the Reagan administration intends to do very little about the deficits, but rather, 15 months from now, to turn them over to the next president. But how to get through those 15 months without an economic breakdown?

Last winter the major industrial countries entered into the Louvre agreement to hold exchange rates more or less where they were. To do that requires the others -- essentially the Japanese and the Germans -- to finance the American trade deficit and, through it, the budget deficit. The budget deficit was declining rapidly earlier this year, but in the fiscal year that started Oct. 1, in the absence of any further legislation, it will start upward again. This autumn the Germans evidently began to resist the suggestion that they would be required to finance this election-year holiday from economic policy in the United States, particularly since the consequences would be inflationary both there and here.

The quarrel with the Germans broke very audibly into public hearing last week. The secretary of the Treasury, James A. Baker, hinted heavily that the United States would let the dollar's exchange rate drop further if the Germans refused to cooperate. The eruption of this quarrel, and the various subsequent statements by the people involved in it, seem to have been the events that precipitated the great slide in the world's stock markets.

Secretary Baker has now made a hasty trip to Germany, and the Germans, recognizing the scale of the emergency, have responded handsomely. Things have been patched back together -- temporarily.

But the point remains, sharp and uncomfortable as ever. The rest of the world is not going to allow the United States to continue postponing all action on its deficits for another 15 months because American politicians find it inconvenient to make difficult decisions before an election. This country has a choice. It can take the initiative to bring its economy into better balance or it can let the markets do it. Letting the markets do it will plunge the world further into a process that, like this week's crash, will leave the world a great deal poorer.