On Sunday's "This Week," Carly Fiorina feebly trotted out an old GOP canard: that the "highest corporate tax rate in the world" is to blame for our stubbornly-high unemployment. In fact, the effective tax US corporations pay is much lower than most industrial nations. This is how a corporation like GE paid effectively no taxes in 2010.

Well, Paul Krugman would have none of it.

FIORINA: ...I said there were three structural issues in the economy. One is small business. There are two others.

The rest of the world has also changed. And the two other structural problems in our economy are we now have the single highest business tax rate in the world. Guess what?

With the highest tax rate in the world, we see the same thing around the world that we see in states -- states with lower tax rates have more jobs, more people. People leave states with higher tax rates. The data is crystal clear. [...]

KRUGMAN: Just..

FIORINA: -- a robust recovery.

(CROSSTALK)

KRUGMAN: Nothing you said about business taxes is actually true.

FIORINA: Everything I said...

(CROSSTALK)

FIORINA: -- about business taxes...

KRUGMAN: -- we can have that discussion (INAUDIBLE) place...

FIORINA: -- is true.

KRUGMAN: But -- but it's not true. If you look at the actual tax collections...

FIORINA: This isn't an academic discussion. It's clear it's true.

KRUGMAN: If you look at the actual tax collections in the United States on business, they're lower than -- than other advanced countries. And if you look at the alleged finding that high business taxes cause job losses in states, it -- it goes away -- on even the kick the tires, even slightly and the whole thing falls apart. It's just not true.

Beautiful.

I really don't know why Republicans think they can get away with spouting falsehoods when Krugman's on the show, but I hope they keep doing it.