There has been an interesting shuffle in the last few months as the Reagan administration, which once promised to balance the budget and eliminate the deficit, discovered that wasn't going to happen. Then we began to hear conservative Republicans explaining away the deficit in terms seemingly invented by liberal economists such as Walter Heller. "It's not really that bad," the line goes, "when looked at as a percentage of GNP."

Gross national product, as we all remember from Economics 101, is the total of goods and services produced by the country. The record $91.5 billion deficit (or $91,500,000,000), it says in the back of the new fiscal 1983 budget (which assumes that the president will get his way on various program cuts), will come in at 2.7 percent of GNP. The smaller $66 billion deficit in 1976 was 4 percent of GNP, thus really larger.

The total budget will be 22.1 percent of GNP. The administration would like to get that down to around 19 percent, where it used to be before the Great Society robbed us of our initiative. The projections for the years ahead show the budget moving slowly in that direction, but still missing it by 2 percentage points in 1985.

Receipts are going to be 19.4 percent of GNP, and they ran 21 percent in 1981. They are supposed to drop to about 19 percent by 1984. So the administration has taxes right where it wants them, at 19 percent. The problem is expenditures. The difference is the deficit. Remember, now, it's not really all that bad (as a percent of GNP).

Seriously, folks, it's not just a game. Many economists regard percentage of GNP as one of the best measuring sticks of expenditure because it avoids the apples and oranges problems that occur when one year's dollar is compared with the inflated dollar of another year.