Why are cellphone plans so much more expensive in the United States than in Europe? It seems a simple question. But the search for an answer took Thomas Philippon on an unexpected journey through some of the most complex and hotly debated issues in modern economics. Ultimately, he reached a surprising conclusion: American markets, once a model for the world, are giving up on healthy competition. Sector after economic sector is more concentrated than it was twenty years ago, dominated by fewer and bigger players who lobby politicians aggressively to protect and expand their profit margins. Across the country, this drives up prices while driving down investment, productivity, growth, and wages, resulting in more inequality. Meanwhile, Europe--long dismissed for competitive sclerosis and weak antitrust--is beating America at its own game. Philippon, one of the world's leading financial economists, did not expect these conclusions in the age of Silicon Valley start-ups and millennial millionaires. But the data from his cutting-edge research proved undeniable. In this compelling tale of economic detective work, we follow him as he works out the basic facts and consequences of industry concentration in the U.S. and Europe, shows how lobbying and campaign contributions have defanged antitrust regulators, and considers what all this means for free trade, technology, and innovation. For the sake of ordinary Americans, he concludes, government needs to return to what it once did best: keeping the playing field level for competition.