The big news in health care last week was the disclosure that CVS Health Corp. — owner of a vast network of drug stores — is considering buying Aetna Inc., one of the nation’s largest health insurers, for roughly $66 billion. It’s undeniably important, but why? Clearly, economic concentration in health care is growing. The possible CVS-Aetna hookup is just …

There are a lot of question marks about Facebook. It’s not clear whether its effort to remake itself into the world’s new living-room television will pay off. It’s not clear whether it can make money from the billions of people using its messaging technologies, WhatsApp and Messenger. And it’s not clear whether Facebook can stay relevant as people find other …

Much about Russia’s online efforts to roil the 2016 US election remains murky. But as executives from America’s top social-media companies — or more precisely, their lawyers — testified before Congress this week, two things became clear. First, the problem is much greater than previously admitted. And second, the companies in question have little incentive to solve it. In two …