If someone’s pay suddenly doubles, she may lose rental assistance, child care subsidies, and more. In L.A., a worker who currently makes $9 an hour and works 40 hours a week (which is not a given, but that would be a full-time workload) will earn $360 a week, or about $1,440 a month and $18,720 a year, before taxes. If that worker is a mom with two children, she is below the poverty line. She qualifies for a bevy of federal and state programs like food stamps, rental assistance, child care subsidies, health care for her children, and Medicaid because...