Allan Sloan used his column today to explain a simple but often overlooked point, when interest rates rise, bond prices fall. This means that if long-term interest rates rise substantially in a few years, as the Congressional Budget Office predicts, then the bonds issued at very low interest rates today will be selling at large discounts.

The implication of this fact is that in 2015 or 2016, the Treasury would be able to purchase back much of the debt issued today at substantial discounts. This would allow it to drastically reduce the government's debt at no cost. For example, if it bought back debt with a face value of $4 trillion at an average discount of 20 percent, it could instantly eliminate $800 billion in debt, reducing the debt to GDP ratio by almost 5 percentage points.

This step would be pointless from either an economic or financial standpoint since it would not change the interest burden facing the country, but it should make many of the deficit cultists happy. Since these cultists, who largely control the economic debate in the United States, assign some mystical power to specific debt to GDP ratios, they should be pacified by the knowledge that we can buy bonds back at a discount to keep the debt burden under their magic number. This route is much simpler than raising taxes or cutting spending.