Minimum wage hikes are accelerating the trend toward automation—and fewer workers—in services.

See The Employee of the Month Has a Battery by Michael Saltsman, WSJ, 1-29-14.

"Steady federal and state increases to the minimum wage have forced employers in retail and service industries to rely on technology as the government makes entry-level labor more expensive"

"Self-service soda machines, available at fast-food restaurants since at least the late 1970s, were a labor-saving device. Even coffee carafes left on the table for customers to serve themselves allowed restaurants to reduce the staff needed to fill cups. More recently, major restaurant chains such as Bob Evans and Chili's have updated their service model to eliminate bus boys, relying on servers to clear tables themselves."

"At some Target and Macy's locations, customers can check their own prices, as well as check themselves out at self-service kiosks after shopping. The Bureau of Labor Statistics reported in 2012 that the number of these establishments has grown by 23% over the last 10 years, while total employment at the firms has fallen by 6%."

"computerized menus as the top tech trend for 2014. Airports in locations like New York City and Minneapolis now feature "restaurants" that are waitstaff-free. In 2011, McDonald's announced it was replacing human cashiers with touch-screen alternatives at more than 7,000 European locations."

"Profit margins in restaurants range from 3%-6%. They are even more modest at grocery stores, at 1%-2%."

"Companies must choose between increasing prices or reducing costs to maintain limited profit margins."

"And in localities such as Seattle and San Francisco, $15 an hour—which translates to an entry-level wage of $30,000 a year—is being seriously entertained. The small airport town of SeaTac in Washington already passed a $15 an hour minimum wage in November. It is not surprising that companies are urgently seeking labor savings that don't dramatically alter the customer's experience."

"But the flip-side of more efficiency is a 20%-25% drop in the number of waitstaff necessary to run a restaurant."

"unemployment for young adults age 16-19 has hovered above 20% for more than five years."

" San Francisco-based Momentum Machines has a burger-flipping robot that replaces three full-time kitchen staff, makes no wage demands and stages no walkouts."