More than 20 years ago, executives at rival auction houses Sotheby’s and Christie’s were found guilty of coordinating a massive price-fixing scheme. Leaders from the companies held covert meetings, where they set identical commission fees. Today, active antitrust cases show that the ways in which companies might conspire are changing. Algorithms can replace secret meetings, but U.S. regulators say it’s still collusion, whether it’s a human or a bot pulling the strings. Marketplace’s Lily Jamali spoke to Joe Harrington at the University of Pennsylvania’s Wharton School about how antitrust law holds up against new technology.