Still, not everyone agrees. The nonpartisan Congressional Budget Office said in a report last year that an increase in the federal minimum wage to just $10.10 an hour could raise the incomes of 16.5 million workers. On the downside, the agency warned such a move could also result in the net loss of 500,000 jobs.  Separately, Buffett has repeatedly said imposing a minimum wage hike wouldn't solve income disparities, opting for changes to the tax code instead.  Read MoreBuffett talks firing, wages and eating like a kid  For Los Angeles and other cities, Reich dismissed predictions that higher wages will result in fewer jobs, citing the multiplier effect.  "Minimum wage workers, because they spend almost everything they're getting in terms of wages, that spending is local spending that stimulates creation of new jobs in the area," Reich said.  The federal minimum wage has been $7.25 an hour since July 2009.  Last week in a Wall Street Journal opinion piece, Buffett, suggested an alternative to raising the minimum wage. Berkshire Hathaway's chairman wrote he believes an expansion of the Earned Income Tax Credit (EITC) is a better alternative.  The EITC is a federal benefit that subsidizes low-income workers by reducing the amount of tax owed from wages. Reich, like the think tank Brookings, backed the credit as an important tool to helping lower-income families.  "People don't realize it," but the Earned Income Tax Credit is "the largest anti-poverty program right now in the United States," he said.  "It is a very good and important program; it is a wage subsidy for people at the bottom," he added.  Reich, however, also said that "it's the combination of the earned income tax credit and the minimum wage and ideally an increase in both that really is the best. "
Former U.S. Labor Secretary Robert Reich is joining the chorus calling for a pay raise for the lowest-paid American workers.