I assess the effect of recent U.S. airline mergers on productive efficiency and market power. I recover productivity, markup, and marginal cost estimates for each airline using production and cost data. I then employ these estimates, a panel event study design, and synthetic control methods to...

In 2020, the Department of Justice (DOJ) filed an antitrust suit against Google alleging that Google has unlawfully monopolized the markets for general search services, search advertising, and general search text advertising. The complaint raises questions involving market definition, monopoly...