For the past week I have been discussing different aspects of our alarming debt problem as vividly illustrated in a recent report from the Congressional Budget Office  (see chart below).  My last post discusses what I call the Buffett Model:  G > D, meaning that as long as nominal growth G (real growth plus inflation) is greater than the deficit D, then the accumulated debt will decrease as a percentage of GDP and the debt is said to be “stabilized”.  This, of course, is what has happened in the U.S. historically after all of our major wars and especially after WWII (see below).  The problem is that our current situation in 2014 appears much bleaker going forward because the debt is projected (by CBO) to just keep on growing indefinitely.
Today I look at a broader model, the so-called BRITS model:  R + I > (S – T) + B   where

• B = borrowing costs
• R = real growth
• I = inflation
• T = taxes
• S = spending.

The BRITS model reduces to the Buffett model by letting G = R + I and D = (S – T) + B.  The value of this more general model is to show the relationship between all five of these important variables.  To meet the objective of stabilizing debt, according to this intuitive model, we should increase both R and I and decrease S – T and B.
The Federal Reserve is involved by keeping B as low as possible and making sure that I is large enough (but not too large or other problems will occur).  Congress can help by cutting spending or raising taxes but, of course, both of these actions are hard to do politically.
If real growth R is high enough then the desired inequality will hold and debt will be stabilized.  But how is this accomplished?  The Fed has been trying to increase growth through quantitative easing but it’s not working very well.  Many economists think that it would be more helpful for Congress to implement broad based tax reform, whereby tax rates are lowered and loopholes and deductions are closed in a revenue neutral manner so that overall tax revenue remains the same.  But nobody wants to lose their own deductions so this is hard to do.
As much as faster growth will help, it is still critical for Congress to get spending under control.  The above chart from the Heritage Foundation shows that under current trends by 2030 federal spending will have increased so much that all federal tax revenue will be spent on just entitlements and interest payments alone!  Since this is unrealistic, some sort of a major new crisis is likely to occur before 2030!
Conclusion: The BRITS model helps to understand the complexity of our debt problem and some of the steps that need to be taken to alleviate it.  I will return to it in the future.