Although the interest rate on the national debt is currently about 6 percent, that's not what you're paying. You're really paying something closer to 4 percent. Here's why: The people who collect interest on the national debt must pay taxes on that interest— effectively paying about 1/3 of the interest to themselves. The rest of us have to come up with only the remaining 2/3. So even if you manage to get a 6 percent Visa card, you're still getting a better deal on the national debt. That means the national debt amounts to a net transfer to borrowers and hence must also amount to a net transfer away from lenders.

A few years ago, I wrote a brief technical exposition of this point for private circulation to a few economists. The tone is flippant, but the point is serious; if you want to wade through the technicalities (and the flippancies), have a look here.