The effect of raising e-book prices from an average of $9.99 to $12.99 or more raises publisher profits, Cooper wrote in his letter. E-books are cheaper to produce and distribute, leading book publishers to increase profits even as revenue is flat, he said.

"As technologies lower the cost of production and distribution, a scrum develops over the social surplus that is released," he wrote. "The sellers of information goods seem to think that because consumers were willing to pay a high price for their physical products in the past, they can keep the price high for digital products and pocket the cost savings as increased profit."

He called on the antitrust committee to pay close attention to e-book prices.

The IDG News Service