WITH journalists as well as social scientists continually on the lookout for new trends, the public is regularly treated to the discovery of social "revolutions." One of the latest concerns women and work. In October 2003, Lisa Belkin detected an "opt-out revolution" in her New York Times Magazine article about accomplished women leaving high-powered jobs to stay home with their kids. Six months later, reports on the revolution were still going strong. For example, the March 22, 2004 cover of Time showed a young child clinging to his mother’s leg alongside the headline, "The Case for Staying Home: Why More Young Moms Are Opting Out of the Rat Race." But the evidence on this score is thin. Both the New York Times and Time stories are based mainly on evocative anecdotes. Princeton college graduates with law degrees from Harvard staying home to change diapers may be absorbing as a human-lnterest story. But as the saying goes, the plural of anecdote is not data.