This is a Keynesian and Monetarist view of budgets. The idea is that IF you balance the budget (they often don't think this is ever a great idea anymore) then it should be balanced over the ups and downs of the business cycle.
So let's say a business cycle starts up again and somehow the government doesn't spend all that extra money before it comes in and there is surplus. Now booms are followed by an inevitable bust no matter what anyone tells you when the next one starts up.
Keynes argued that you should spend during busts to keep aggregate demand up and let the economy recover. So you run a deficit during this time. If you consider a balanced budget then they might argue that you should balance it with consideration to short term gains and losses.
If you're interested this video is a fun and very accurate way to learn about two different views of the business cycle:
The federal budget process and the economic reality on the ground are out of phase. To achieve stability in the system, these processes need to be brought more into phase.
Put another way: the budget contains a de facto representation of the current economic position as well as economic "velocity" and higher derivatives. In forming the budget, legislators encode these values. In many cases, these values over- or under-shoot reality with poor consequences.
tl;dr: Balancing the budget is a stabilization criterion and bringing the active driver into synchrony with the driven body (the economy) should improve stability.
It's a question about how a balanced budget amendment should work (if we had one). Balancing the budget every year would be a worse idea than requiring it to balanced over several years.
"If the federal budget is to be balanced, it should be done over the business cycle rather than yearly. (85%)"