DoorDash announced on October 29 that it will buy Instacart for about $17 billion. Mergers and acquisitions usually happen for the benefit of shareholders, but to get the deals passed by regulators, companies say that they are for the benefit of consumers and employees. So it’s no surprise that the DoorDash announcement leads with benefits for consumers, delivery drivers, and local retailers.

Consumers And Drivers Will Get The Short End Of The Stick

Let’s be clear: DoorDash is buying a competitor and is using its inflated stock price to do so (its price-earnings ratio is a whopping 90+, in contrast to Amazon’s, which is around 20). DoorDash’s announcement called out several outcomes of the acquisition: more choice for shoppers, better exposure for stores, two memberships for the price of one, and more ways to earn for drivers and delivery personnel. Much of what is likely to happen is microeconomics 101:

Less choice for shoppers over time.…