To some extent, people’s proximity to their parents is a reflection of opportunity: The biggest determinants of how far people venture from home are education and income. Those with college and professional degrees are much more likely to live far from their parents than those with a high school education, in part because they have more job opportunities elsewhere, including in big cities.

Wealthier people can afford to pay for services like child and elder care, while low-income families are more likely to rely on nearby relatives. But middle-class and educated two-income couples — say, a schoolteacher and a nurse — are also more likely to live near parents, said Robert A. Pollak, an economist at Washington University’s Olin Business School in St. Louis, who studies the economics of family.