Can the government stop companies from increasing prices solely because competitors increased their prices? In a recent paper, Brendan Ballou, a U.S. Department of Justice trial attorney, argues that the Federal Trade Commission (FTC) needs to do just that. Ballou asserts that a new method of price-fixing regulation can reduce tacit collusion. He proposes a “no-collusion” rule under which no business can raise “its prices solely because a competitor has done so.” Ballou asserts that, in a world of concentrated industries, it is easier for companies to use a range of public information—typically “public announcements, investments, and algorithms”—to determine how their competition will change their prices, even without direct communication...