Many who live by themselves are effectively penalized at work too. “Lots of people I interviewed complained that their managers presumed they had extra time to stay at the office or take on extra projects because they don’t have family at home,” Eric Klinenberg, the author of the 2012 book Going Solo: The Extraordinary Rise and Surprising Appeal of Living Alone and a sociologist at NYU, told me. “Some said that they were not compensated fairly either, because managers gave raises to people based on the impression that they had more expenses, for child care and so on.”

And if many workers who live alone end up making less money, as consumers they face less favorable pricing options than other shoppers. Buying larger quantities of food at the grocery store is usually cheaper, but as DePaulo pointed out, people who live alone might not get through perishable items quickly enough. (She wishes more stores would let people buy only as much of something as they please, instead of locking them into certain packaging sizes.) Even when a consumer good such as paper towels can’t spoil, people with a small home might not have the space for a stockpile.

The bias against solo consumers runs deep: Recipes are rarely written for a single diner, and DePaulo said that she has heard from single people who have had trouble booking restaurant reservations for one. Also, some aspects of travel, particularly lodging, are much more expensive, per person, for single people. These all may seem like small annoyances, but in practice they are regular reminders that American society still assumes that the default adult has a partner and that the default household contains multiple people.

More concerning, some health-care protocols are essentially built on the assumption that a patient lives with someone who can support them.