Krugman:

Don’t like the platinum coin option? Here’s a functionally equivalent alternative: have the Treasury sell pieces of paper labeled “moral obligation coupons”, which declare the intention of the government to redeem these coupons at face value in one year.

It should be clearly stated on the coupons that the government has no, repeat no, legal obligation to pay anything at all; you see, they’re not debt, and therefore don’t count against the debt limit. But that shouldn’t keep them from having substantial market value.

When your only tool is a hammer, everything looks like scads of make-beleive dollars.

Forget the currency — the thing truly debased is Paul Krugman.