MAHACHAI, Thailand — At an age when she should have been in a classroom, Thazin Mon discovered her knack for peeling shrimp. To help support her Burmese migrant family, the 14-year-old pulled 16-hour shifts, seven days a week, for less than $3 a day. “I am uneducated, so I work. I have to work bravely,” she says.

Although she was the best peeler in the factory, speed was never enough. Mon was beaten if she slowed down, she said, and when she asked for a day off to rest hands swollen with infection, her boss kicked her and threatened rape.