Low-wage workers are routinely denied proper overtime pay and are often paid less than the minimum wage, according to a new study based on a survey of workers in New York, Los Angeles and Chicago, The New York Times reports.

The study found that 68% of the workers interviewed had experienced at least one pay-related violation in the previous work week.

Researchers said one of the most surprising findings was how successful low-wage employers were in pressuring workers not to file for workers’ compensation. Only 8% of those who suffered serious injuries on the job filed for compensation to pay for medical care and missed days at work stemming from those injuries.