"Supersize my pay" has become a unifying protest slogan for fast food workers across the country. This week, quick-service employees in at least eight cities are demanding their wages jump to $15 an hour -- more than double the federal minimum wage of $7.25. Even working full-time for 52 weeks a year, the current minimum falls well below the country's poverty line.

Barely Treading Water

"I don't want to work two jobs, I just want to work one job," said Dejaun Jackson, a 23-year-old Chicagoan who works 38 hours a week at Walgreen's and part time at Chick-fil-A to support his 5-year old son. He makes a little more than $10 an hour at Walgreen's, and just above Illinois minimum wage of $8.25 an hour, but he said that's still barely enough to tread water.

"I wanted to go to school this fall, but I just couldn't do it with [the] outstanding loans" he took out to pay for essentials, he said. Jackson is joining a city-wide strike on Thursday that organizers say will include 60 local businesses.

Lorraine Chavez, campaign spokesperson for Workers' Organizing Committee of Chicago, a union leading the city's protests, said in addition to the $15 wage, striking workers are calling for the right to unionize, for better working conditions and more respect.

"Managers frequently refuse to give workers a 40-hour week. By doing so, they do not have to comply with a lot of labor regulations like paying overtime," even when workers are putting in more than an 8-hour days, she said.

Walkouts started on Monday in New York, Milwaukee, St. Louis and Kansas City. Workers in the traditionally labor-strong Michigan cities of Detroit and Flint postponed plans to protest on Monday, but workers took to the streets on Wednesday. Seattle is the latest city to join that list.

Too Much Turnover

The National Restaurant Association estimates a 75 percent employee turnover rate for fast food restaurants. At an average cost of $3,000 in recruiting and training to replace each employee, the industry considers turnover to be a financial liability instead of an asset.

But for business owners there's a hidden upside to the constant flow of new employees. Aside from keeping wages at low starting levels, the high rotation of young, inexperienced and low-income workers makes organizing a particular challenge, a professor at Northeastern University in Boston, Ed Wortheim, told the Christian Science Monitor.

"Organizing for this large of a group of workers is extremely difficult, and many of these people are not going to stay in and continue the fight," he said. "Many can and will decide to move on and get a job that pays more – ostensibly abandoning ship for the next group of workers to inherit the problem."

Chavez disagrees that rotation is a big barrier for unionization, saying union members in the fast food industry often have multiple jobs and full schedules that can squeeze out time for activism, but membership rolls remain strong.

"What happens is that once they leave one job they just end up at another fast food job and they're still in the union and represented by us," she says. "So there is high rotation. But the work conditions that these workers are facing are simply unbearable. And they have been moved to act."

Young workers face an additional penalty for frequent job changes. According to federal law, workers under the age of 20 can be paid $4.25 during their first 90 days, as long as they don't push other employees out when they join the crew. The average age of a fast food worker rose from 20 in 2000 to 29.5 in 2010, according to the U.S. Census Bureau.

Don't Make Us Replace You With Robots

Fast food companies say a wage increase to $15 an hour would be devastating, causing massive layoffs among the industry's some 13 million employees. Lobbying firm The Employment Policies Institute sponsored a full-page ad in USA Today this week not-so-subtly suggesting the wage hike would force restaurants to cut costs by replacing workers with creepy iPad-faced burger slingers.

In an email interview, Scott DeFife, executive vice president for government affairs for the National Restaurant Association, said strikers should consider the opportunities fast food restaurants provide for first-time workers and those who want to build a career.

"Restaurants operate on very thin profit margins. Significant additional labor costs can negatively impact a restaurant's ability to hire or maintain jobs. The cost of living varies greatly nationwide, while current proposals aimed at doubling the minimum wage would have a significant effect on the private sector's ability to create jobs, especially those typically filled by first-time workers and teens."

A number-crunching business student at the University of Kansas, Arnobio Morelix, recently found that in theory McDonald's would only have to increase the price of each item on their menu by just 17 cents in order to double all of its salaries, which means a Big Mac would cost $6.66 instead of $5.69.

Read More

• A Day's Strike Seeks to Raise Fast-Food Pay (New York Times)
• 'Fight for $15' begins 2nd round in Chicago (Chicago Tribune)
• Schooled by Occupy movement, fast-food workers put demands on the table (Christian Science Monitor)
• Doubling McDonald's Salaries Would Cause Your Big Mac To Cost Just 68¢ More: Study (Huffington Post)