U.S. cities that implemented big minimum-wage hikes to $10 an hour or more in 2015 have seen a strikingly similar aftermath: Job gains have fallen to multiyear lows at restaurants, hotels and other leisure and hospitality venues. The data aren't, for the most part, stark and reliable enough to amount to smoking-gun proof. But Chicago, Oakland, San Francisco, Seattle, Los Angeles and Washington, D.C. — all on the leading edge of the push for big minimum wage hikes — all show worrisome job trends.