Carrying budget documents the size of a New York telephone book, reporters stagger out of the annual budget briefing. They lug away statistical tables that not only reflect the parlous state of the domestic and world economies, but feed the growing debate over what's to be done about them.
Today the problem is global.
Distribution of the administration's budget is like the kickoff in an extended football game. It may involve Congress, the White House - and the nation - in huddles, strategies, and fourth-down dilemmas for the rest of the year.
And now, more than ever, domestic issues are intertwined with foreign ones. For example:
* How much should the administration budget for defense while nuclear arms negotiations resume in Geneva?
* What should the government set aside for social amelioration at home with 10.8 percent unemployment and each 1 percent rise in unemployment adding $25 billion to a bulging federal deficit that worries not only our own financial community but those abroad as well?
* What, if anything, should the US do to ease world recession, when developing countries owe half a trillion dollars to foreign creditors and when, for example, loans by the nine largest US banks to Mexico and Brazil alone just about equal the banks' total reserves and capital?
The budget instrument by which policies like these are hammered out often amazes the rest of the world. In Great Britain the government presents its budget to the House of Commons, which customarily passes it in a week or two. A major change in it by the opposition would bring a new election.
When President Reagan first tangled with the US process in May 1981, he called it ''the most irresponsible, Mickey Mouse arrangement'' he'd ever seen. The procedure grows out of the American system of divided powers. The executive, elected for a fixed term, sends its proposed fiscal blueprint to Congress, which may be dominated by the opposition party.
A new system was introduced in 1974. For the first time a unified budget, attempting to balance expenditures with receipts, was required. Everyone agrees it hasn't worked very well. What surprises some people is that it works at all. With Congress unable to agree on the President's budget (or a compromise version of its own), the Legislature has repeatedly carried on the business of the world's wealthiest nation on a so-called continuing resolution. This means that members agree to disagree.
Even the nomenclature of the budget is bewildering. To measure expenditures of one year against another, calendar years aren't used. Time is measured instead in ''fiscal years'' - a device which may reflect the past escape route by which some Congresses avoided a time limitation. The present fiscal year began Oct. 1, 1982, and is ''FY 1983.''
The President's new budget comes at a troubled time. There is global recession, a huge deficit, clamor to aid the unemployed and failing industries. And there is an ongoing struggle over who's in control in Washington. Who sets the budget? Rep. Richard Bolling (D) Missouri, who has just retired from Congress, calls the struggle ''perhaps as fundamental as was the great change from the Articles of Confederation to the US Constitution.''
Through history, presidents have occasionally refused to spend funds appropriated by Congress. It came to a head when Richard Nixon infuriated Congress by impounding funds. It passed the Congressional Budget and Impoundment Control Act of 1974 that established new procedures. The measure forced Congress to review the budget as a whole and then reconcile individual taxing and spending decisions. But the new budget committees ran into rivalry with the powerful old-line appropriation committees. The contest hasn't been resolved. Mr. Reagan turns loose his new budget in a booby-trapped Congress.
But as Congress debates, it must consider more than ever the world's interdependence:
* Two of five acres of US farmlands produces for export.
* A fifth of US industrial output is exported.
* One in six US manufacturing workers owes his job to exports.
* About a third of US corporate profits derives from firms' international activities.
America is in the global community. It is a kind of self-help, cooperatively managed, international spider-web, each strand sensitive to others.
At the budget press briefing here, reporters look like schoolboys bent under documents, the biggest of which was the ''Appendix'' putting a cost tag on every government agency. It weighs about five pounds.