Perhaps the most concerning red flag came in a preprint posted this month from a team of researchers from U.C.L.A. and the University of Southern California. In states that legalized and enabled online sports gambling, the researchers found, the likelihood of bankruptcy rose by 28 percent — not just among gamblers, whether casual or compulsive, but statewide. Relatedly, average credit scores went down — three times as much in places that enabled online gambling as in places that legalized only in-person betting — and debt collections went up. The effects were larger in low-income communities, which is not surprising: Families with smaller savings will most likely spend a much larger share of those savings gambling than those with more cash to spare, and do so with much less of a buffer to protect against losses.