In theory, people who make lower incomes have a lot to gain from the sharing economy. If you can’t afford, say, a monthly car payment, then hiring a car from a neighbor is the next best thing, and there are now many ways to do that, like Getaround. Research by N.Y.U. researchers Samuel Fraiberger and Arun Sundararajan last year found that ride-sharing has a “disproportionately positive effect on lower-income consumers” mostly because poorer groups are…