To be clear, having more space does generally lead to people saying they’re more pleased with their home. The problem is that the satisfaction often doesn’t last if even bigger homes pop up nearby. “If I bought a house to feel like I'm ‘the king of my neighborhood,’ but a new king arises, it makes me feel very bad about my house,” Bellet wrote to me in an email.

The largest houses seem to be the ones that all the other homeowners base their expectations on. In neighborhoods where the biggest houses are more modest, Bellet told me, expanding the size of one’s house can be 10 times as satisfying as undertaking such an expansion in a neighborhood where the biggest homes are palatial.

Bellet sketches out an unfulfilling cycle of one-upmanship, in which the owners of the biggest homes are most satisfied if their home remains among the biggest, and those who rank right below them grow less satisfied as their dwelling looks ever more measly by comparison. He estimates that from 1980 to 2009, the size of the largest 10 percent of houses increased 1.4 times as fast as did the size of the median house. This means that the reference point many people have for what constitutes a big home has shifted further out of reach, just as many other lifestyle reference points have shifted in an age of pronounced wealth inequality.

To reach these conclusions, Bellet scraped data on millions of American homes from the real-estate website Zillow, and grafted it onto data from the American Housing Survey, which has been conducted by the Census Bureau since 1973 and records, among other things, how big new homes are and how satisfied homeowners are with their houses. The merging of these two sources allowed Bellet to examine how envy might play out on the level of the neighborhood block, and to study, for instance, whether being close to an enormous new house makes one less satisfied with one’s own home. (It appears to.)

Bellet was looking in particular at the links between the size of one’s home and one’s satisfaction with it. But it could well be the case that having a bigger home is beneficial in ways he wasn’t focusing on. “There could be positive impacts on, say, long-run life satisfaction more generally if McMansion neighborhoods also have better schools, which improves the future outcomes of homeowners’ kids,” Bellet wrote to me.

Of course, expansive homes could be unfulfilling in other ways. “The big house represents the atomizing of the American family,” a historian of landscape development told NPR for a story on gargantuan American homes back in 2006. “Each person not only has his or her own television—each person has his or her own bathroom … This way, the family members rarely have to interact.” It’s comfortable, in a way, but maybe also lonely.

In this sense, the story of American home sizes in the past half century is a story of shifting norms. Fifty-plus years ago, a one-bathroom house or a bedroom that slept multiple siblings might have felt cramped—but it also probably felt normal. Today, many Americans can afford more space, and they’ve bought it. They just don’t appear to be any happier with it than with what they had before.

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