Failure to achieve a 1983 budget compromise could carry a very high economic price tag, which millions of Americans would have to pay.
A signal now goes out to the nation, and especially to the financial community, that budget deficits in the years ahead will be larger--perhaps much larger--than the Reagan administration had projected.
''The breakdown of negotiations,'' said a top-level congressional source, ''is very unfortunate, because a lot of good things are happening in the economy.''
Inflation is down, he said, and so are oil prices. Wage settlements tend to be more in line with productivity than they were in recent years.
''All this,'' he said, ''was setting a very nice foundation for recovery,'' which now risks being undermined by lack of agreement on how much money the government should spend and where it should be spent.
Collapse of the White House-congressional budget talks spells bad news for the economy in a number of ways, according to some experts:
* Interest rates are likely to remain high, threatening to slow down or even choke off whatever economic recovery may start later this year.
Huge budget deficits require the US Treasury to borrow so heavily from the nation's pool of savings that private borrowers tend to be crowded out. The resulting competition drives interest rates higher.
* If economic growth is slow, unemployment--now 9 percent of the labor force--will remain substantial.
* Troubled industries sensitive to interest rates--notably housing, autos, and industries dependent on them--will find it harder to turn around.
One or more major companies, said Commerce Secretary Malcolm Baldrige recently, may go under in the process. Bankruptcies among smaller firms are climbing.
The budget process now reverts to Congress, where House and Senate budget committees separately will begin to fashion budgets for fiscal 1983, which begins Oct. 1, 1982.
In the normal course of events, those separate documents would be passed by their respective chambers, reconciled or fused into one budget document by a conference committee, passed again by full House and Senate, and sent to Mr. Reagan for signature.
One document before the budget committees as they buckle down to work is the 1983 budget sent to Congress by Mr. Reagan in February. This called for a ''deficit reduction plan''--i.e., spending cuts, user fees, modest tax increases , and ''management initiatives'' - totaling $55.9 billion.
The White House estimates that its '83 budget would suffer a deficit of $101. 9 billion, if Congress gave Reagan everything he sought.
Disagreement between Democrats and Republicans--and intramurally in each party--on White House budget priorities launched the acrimonious and ultimately fruitless search for compromise.
The final step was Mr. Reagan's ''extra mile'' journey to Capitol Hill to confer Wednesday with House Speaker Thomas P. O'Neill Jr. (D) of Massachusetts, Senate Majority Leader Howard H. Baker Jr. (R) of Tennessee, and other congressional leaders.
A worst-case scenario ensues if House and Senate can't agree. Then the US would enter fiscal '83 on a ''continuing resolution,'' authorizing spending at fiscal '82 levels.
''This,'' said a budget expert, ''would guarantee a huge deficit,'' estimated by congressional and White House officials at roughly $180 billion for fiscal 1983, rising to about $215 billion the next year, and to more than $230 billion in fiscal 1985.
Why would a larger deficit be guaranteed? ''Because,'' the source said, ''you would not have any spending cuts, since the continuing resolution effectively continues spending at current levels. But you would have the income tax cut due July 1, which is not affected by the budget impasse.'' Net effect would be smaller revenues with which to pay for higher spending.
''That,'' said the source, ''is why both sides accepted the $180 billion deficit figure for 1983, and higher for the outyears, if nothing were done.''
Because the situation is so serious, some lawmakers believe that a consensus will be found within Congress to forge a 1983 budget.
''Something will be done,'' said a Congressional source close to the negotiations, ''to shave $40 to $50 billion from the 1983 deficit, bringing it down to $130 or $140 billion.''
Such an achievement, in his view, at least would ameliorate the bad effects stemming from a complete budget impasse.