Google rejected Tuesday the results of a study released months ago which predicts a 22 percent ad price increase from Yahoo's search-ad deal with Google. The company's chief economist, Hal Varian, wrote on Google's official blog about what he calls misconceptions based on the July report by SearchIgnite and other sources.

Hal Varian writes that the ad consultancy firm makes several flawed assumptions and uses questionable methodology in developing the report, especially because it presumes that advertisers will be getting the same performance from the same ads, just at higher prices, while in fact the deal will bring better performance at prices set by advertisers themselves, through the auction process.

A severe flaw of SearchIgnite's dubious paper is that it makes a key claim which isn't in fact true. The ad consultancy firm says that Yahoo! will have the ability to see whose ads are priced higher, its own or Google's, and then decide which ads to serve, which is not true. Neither company will be able to see the current auction prices for the other one's ads.

The debunking of SearchIgnite's flawed report is part of Google's push to revamp the image of its deal with Yahoo in the wake of some potential regulatory problems in both the United States and Europe. Antitrust regulators are keeping a close eye on the partnership. The U.S. Justice Department, various state attorneys general and regulators in Canada and Europe are currently looking at the deal.