There are a lot of upsides to urban density — but viral contagion is not one of them. Also: a nationwide lockdown will show if familiarity really breeds contempt. And: how to help your neighbor.

As cities become ever-more expensive, politicians and housing advocates keep calling for rent control. Economists think that’s a terrible idea. They say it helps a small (albeit noisy) group of renters, but keeps overall rents artificially high by disincentivizing new construction. So what happens next?