The concept is similar to that of an application for a mortgage. The borrower needs a reasonable "debt payment/income ratio" to qualify. The more pre-existing debt one has, and the more of one's income it takes to service that debt, the less creditworthy the individual becomes.
After World War II, the debt to GDP ratio was 120%. Why wasn't it a disaster then? The answer: 1) the war had ended and spending was reduced and 2) the economy grew faster than the debt. By 1974, the debt to GDP ratio had fallen to 32%. It rose after that, to 66% in 1996 after the recession of the early 1990s. Then it fell to 56% during the strong economic growth years of the late 1990s and the spending control emphasis of the Congress -- which was accepted and then embraced by President Clinton.
By 2008, as a result of debt growth outpacing economic growth during the George W. Bush presidency, the ratio rose to 70%. Then came the financial crisis and Great Recession, with weak economic growth in its aftermath. The debt to GDP ratio now stands at more than 100%, a level that makes the international community nervous.
There are two key concepts here: 1) controlling the size of the fiscal deficit to control the growth rate of the debt (this implies confronting the entitlement growth issues) and 2) growing the economy fast enough to accommodate a rising level of debt (which implies that the rate of economic growth be faster than the growth rate of the debt).
Spending, entitlement growth, the growth of the debt and economic growth are all interrelated. If confronting the entitlement issues is off the table in the current political negotiations, as it appears to be, then the only chance at avoiding a true debt crisis is for the economy to grow.
The longer the politicians bicker about the budget, taxes and spending, the more that uncertainty will hold back economic growth. That clearly shows up in all of the business surveys.
For everyone's benefit, it behooves Washington to put some degree of certainty back into the business markets, at least for a time period that will allow a return on new capital deployment.
The longer-term question is whether or not federal spending growth will allow the debt to GDP ratio to decline. If it does, then the fiscal issues in Washington will disappear, just as they did post-World War II. If it doesn't, one should prepare for those "invisible hand" economic implications.
This article was written by an independent contributor, separate from TheStreet's regular news coverage.