Rob Austin and his wife, Natalia, have a 10-month-old son, healthy incomes and plenty of cash in the bank for a down payment on a house. But they are happily renting a townhouse in Pasadena, Calif., with no plans to buy for now, given the frothy prices in their area. “As long as there is such a disconnect, where a couple like my wife and me have to put down a gargantuan down payment and still have a large monthly payment to get into a decent, and not necessarily nice, house, that is a game we don’t wish to play,” said Mr. Austin, a 39-year-old business manager at a biotechnology company. “When home price-to-income levels come back to a more normal level, when that happens, then we will be the first to jump in. If that never happens, that is O.K.” More American households are renting, across all income levels and generations, for different reasons. But when homeownership is the centerpiece of the American dream, most of us have internalized certain ideals: Buying a home builds e...