Noemi Castro has worked at Kmart for three years.
She says her unpredictable schedule, which usually comes with short notice, is unsustainable.
"Not being able to know how many hours you work can get in the way of paying rent, bills and even daily necessities," said Castro.
To give you a sense of the fluctuation in hours for retail workers, last week Noemi Castro worked 26 hours at Kmart. This week, she's scheduled to work eight hours.
"If you don't know the schedule of your first job, how can you get a second?" said Castro.
UCLA's Labor Center surveyed 818 retail workers in Los Angeles and found that unstable and unreliable hours are prevalent. It was the first comprehensive study done of the second-largest employment sector in the city. Over 140,000 Angelenos work in retail.
"There were some great policies passed in this city like the minimum wage increase, the paid sick time - but if you don't get the hours, you're not going to realize those benefits," said Saba Waheed, research director for the UCLA Labor Center.
The labor center hopes the study will give a voice to workers, most of whom are non-union, not getting enough hours to support themselves.
The study also provided insight into why this is happening.
"Rather than getting full-time workers and giving people regular hours, they hire a lot more people and schedule them for a lot less time," said Waheed.