What does it take to be middle class in America? The timely answer seems to be not home ownership or a college education, but a good job. In a survey released late last month, 86 percent of the 2,000-plus Americans polled by the Pew Research Center put a secure job at the top of their list of requirements to qualify for the middle class. The next most-popular answer was health insurance, which made the list for 66 percent of respondents in the survey, conducted in July. Owning a home was considered a sign of membership in the middle class by...