Home builders and other real estate companies are increasingly betting that would-be home buyers frustrated with a shortage of homes for sale and runaway prices will settle for renting their slice of the American dream. Although individual homeowners and mom-and-pop investors still account for the vast majority of single-family rental homes, home builders have stepped up construction this year of new houses for rent. In the third quarter, builders broke ground on 16,000 single-family homes slated to become rentals. That’s the highest quarterly total of housing starts for built-to-rent homes going back to at least 1990, according to an analysis of U.S. census data by the National Assn. of Home…