In May, Facebook introduced an archive containing political ads shown on Facebook and Instagram. It includes information on the ad costs, viewership and certain demographics of the ad audience. "This is by far the best transparency effort that any of the social media platforms have given us," said Laura Edelson, a doctoral student at New York University who researches political ads on social media. Rob Leathern, director of product management at Facebook, said the archive and other changes would "help prevent the abuse" of the company's advertising tools.