"How we support our workers and their families impacts Californians who might never set foot on one of our campuses," said UC President Janet Napolitano, who oversees 10 campuses, including UCLA and Berkeley. "It's the right thing to do."
The 240,000-student University of California becomes the nation's first public university to commit itself to the $15-an-hour wage that has become the rallying cry of many labour groups in recent months.
So far, the cities of Los Angeles, Seattle, San Francisco, Oakland and Berkeley have approved phased-in increases that eventually will take their minimum wage to $15 an hour, or about $31,200 a year. On Tuesday, Los Angeles County, the nation's most populous county, voted to craft a law to do the same over five years.
In New York, the state Wage Board endorsed a proposal to set a $15 minimum wage for workers at fast-food restaurants with 30 or more locations. The increase would be phased in over three years in New York City and over six years elsewhere.
Gov. Andrew Cuomo's administration has the final say, and he has signalled his support. New York would become the first state to single out a specific industry for such an increase. The state minimum wage is now $8.75.
"You cannot live and support a family on $18,000 a year in the state of New York — period," Cuomo said at a New York City rally celebrating the proposal. "This is just the beginning. We will not stop until we reach true economic justice."
Restaurant owners warned that higher wages could force them to raise prices, cut employee hours and hire fewer workers, and they said they may challenge the move in court.
"Singling out fast-food restaurants while ignoring other industries that hire workers who are paid under $15 is unfair and discriminatory," said Jack Bert, who owns seven McDonald's restaurants in New York City.
But Rebecca Cornick, a 60-year-old woman who makes $9 an hour at a Wendy's in Brooklyn, said, "If I made $15, I could pay my rent on time, I could put food on the table, I could hold my head up."
At the University of California, the hourly wage earners include students and full-time contract employees who work in dining halls, dorms and bookstores or labour as gardeners, housekeepers and custodians. Many start at the state minimum wage of $9 an hour.
Napolitano said she will boost that to $13 in October for employees who work at least 20 hours a week and will raise it some more in stages to $15 by the fall of 2017.
About 3,200 UC employees and a much larger but undetermined number of people employed by outside contractors at the university will receive the higher wage, UC said. The university is California's third-largest employer, with a staff of 195,000.
"I just thought it was important for a public university to plant the flag here for low-wage workers and a more livable wage," said Napolitano, who was President Barack Obama's homeland security secretary before she assumed leadership of the university nearly two years ago.
Napolitano's plan does not need approval from the university's governing Board of Regents.
The higher minimum-wage argument has gained traction amid concerns over the shrinking middle class and rising income inequality.
Supporters argue a higher wage floor will help lift the working poor into the middle class. Opponents warn higher wages will kill jobs and lead to higher prices. Sixteen states have passed laws barring local governments from setting their own minimum wage.
Democrats, including presidential front-runner Hillary Rodham Clinton, have said they support a higher federal minimum wage, which is currently $7.25 per hour.
Vice-President Joe Biden promoted a higher minimum wage of at least $12 an hour during a stop Wednesday at a washroom equipment manufacturer in Los Angeles, where he chatted with employees as they assembled soap dispensers.
Biden said the wage hikes approved by the city's mayor and county supervisors would be "life-changing" for some 700,000 workers in the Los Angeles area.
"Maybe you'll be able to have meat on the table a couple of times a week instead of once a month," Biden told workers at Bobrick Washroom Equipment, whose CEO backed the city's wage ordinance.
Other public university systems, including ones in Washington state, Indiana and Tennessee, have adopted minimum wages higher than those set under state or federal law. But none have committed to going as high as the University of California.
University officials estimated that the raises for workers directly employed by UC will cost $14 million a year, a fraction of the system's $12.6 billion annual payroll. UC said it also expects contractors will pass some of the cost of higher wages onto the university.
The Republican leader of the California Assembly criticized the university's plan to extend the higher wage to outside contractors.
"The university should be teaching engineering, not spending student dollars to practice social engineering by limiting who campuses can do businesses with," Assemblywoman Kristen Olsen said.
In Washington, D.C., meanwhile, election officials approved the language of a proposed ballot measure that would make the nation's capital the first East Coast city to adopt a $15 minimum wage. Supporters will have to gather about 23,000 signatures to get the proposal on next year's ballot.
Klepper reported from Albany, N.Y. Associated Press writer Robert Jablon in Los Angeles contributed to this story.
This story has been corrected to show that the number of affected university employees is about 3,200 instead of 4,200.