INFLATION IS RUNNING a little higher than the administration expected last winter, and the economy is growing a little more slowly. The drift isn't dramatic, but it's a reminder of the central dilemma of American economic policy. It can't do anything about either the growth rate or inflation without making the other worse. Paul Volcker will probably have something to say on the subject when he comes before a House subcommittee this morning to give his semiannual accounting of his monetary management. It will doubtless be one of his last appearances there as chairman of the Federal Reserve Board. The Senate Banking Committee will simultaneously be holding a hearing on the nomination of Alan Greenspan to be his successor.

Mr. Volcker has worked diligently to make Congress aware of the large and increasing influence of the rest of the world on American prosperity. Congress holds the Federal Reserve responsible for interest rates. But the United States no longer has much autonomy in setting the rates. That's another aspect of the same dilemma.

Interest rates are closely tied to the exchange rate of the dollar, and each can do dangerous things to the other. A falling dollar means higher interest. It incites fears of inflation and, more immediately important, it deters investors in Tokyo and London from sending their money here. A steady flow of foreign money is essential to finance this country's federal budget deficit. Without the foreign money, borrowers here -- including the Treasury -- would have to bid much higher for loans from a shrunken pool of lendable money. A lot of people in Congress want to see the Federal Reserve try harder to push interest rates down. But that threatens a further fall of the dollar and paradoxically, in reaction to it, a sudden lurch upward in interest rates -- a lurch like last April's over which the Federal Reserve would have little control.

As Mr. Volcker is likely to tell Congress once again, the solution is to get the federal budget deficit down. The deficit has dropped this year, but the Congressional Budget Office has just given its employers a warning that there's not likely to be much more progress for the next couple of years even if the reconciliation bill with its tax increases is enacted. And President Reagan has sworn to veto it. On one side of the Capitol this morning, Mr. Volcker will describe the most intricate balancing act in Washington while on the other side, the senators proceed with the confirmation of Mr. Greenspan as the man to keep the act in balance