~snip~The success sequence, previously suggested in research by, among others, Ron Haskins and Isabel Sawhill of the Brookings Institution, is this: First get at least a high school diploma, then get a job, then get married, and only then have children. Wang and Wilcox, focusing on millennials ages 28 to 34, the oldest members of the nation’s largest generation, have found that only 3 percent who follow this sequence are poor.A comparably stunning 55 percent of this age cohort has had children before marriage. Only 25 percent of the youngest baby boomers (those born between 1957 and 1964) did that. Eighty-six...