Sleep is a rare commodity for Juan Cortez. Between nights spent clearing tables at a Manhattan nightclub and days running food to customers in a Bronx restaurant, the 42-year-old Peruvian immigrant worries more about finding time for shuteye than job security.

More than 100 miles to the north in the Hudson Valley, Omar Guzman also isn't concerned about staying employed. The 20-year-old migrant farm worker spends his summer days picking peas and cherries, and by fall will be harvesting acres of apples.