The article discusses how firms in the natural gas industry can enter a market without competing directly. They have contracts that give them low costs, so they choose which customers to serve and set prices. The research shows that firms prefer to have a monopoly in part of the market rather than compete for the same customers. This leads to entry without competition, where firms don't enter new markets if a rival is already there. Antitrust rules don't stop this, but a different market setup can encourage competition and lower prices for customers.