Mr. Krugman, for his part, said he did not remember seeing the cover until prepublication copies were sent to reviewers. "I think it was intended to be ironic," he said.
The cover images of Mr. Bush and Mr. Cheney were borrowed from puppets carried by protesters outside the World Economic Forum in New York in 2002. Mr. Krugman said that he took part in the forum and does not share the protesters' views. He noted that his columns have defended free trade and argued that the administration's war in Iraq was not about oil.
"It is a marketing thing, not a statement," he said. "I should have taken a look at that and said, `What are you doing marketing me as if I am Michael Moore? This is silly.' "
Incivility is one thing, he said, but the book cover "may be undignified, which would be a reason to object."
Krugman did not go on to say "If you can't argue with the facts, attack the cover of the English edition." But he should have.