That would depend on how one defines a living wage. The Federal minimum wage is about $7.50/hour. However, an exception is made for people who receive tips, and then the minimum wage is $2.13/hour, based on an assumption the the person involved is receiving tips which make up the difference between $7.50 and $2.13. (Serving at a counter is not seen as a tip situation by the government.) The problem that i see is that tips are given for the service rendered, and i don't see pouring a cup of coffee as rendering any particularly noteworthy service. To my admittedly limited knowledge, people in coffee shops receive at least the minimum wage, and usually somewhat (although not a great deal) more than that. There are a variety of dodges by which the corporate coffee shop chains avoid being responsible employers. One is to assure that their staff are not scheduled for more than 30 hours per week, which absolves them from the responsibility of providing their staff the benefits (health care, primarily) which is provided to management staff. This is not limited to coffee shops, by any means. There are many retail outlet corporations which use the same dodge to avoid providing benefits, and then provide the minimum of benefits they can get away with to management staff whom they then work like dogs.
The issue of what is or isn't a "living wage" is fraught with political considerations here. Many states have a higher minimum wage than the Federal minimum wage, and some municipalities mandate an even higher minimum wage. A rise in the minimum wage was long overdue in the 1990s when the Republicans took over Congress, and they steadfastly resisted any increase in the minimum wage until it became clear that they might suffer at the ballot box, and even then it was like pulling teeth. Many of them were able to get away with continuing to oppose an increase in the Federal minimum wage because the states from which they were elected were paying a higher rate.
Local conditions matter, too. For example, in Columbus, Ohio, there are so many successful restaurants that getting reliable dishwashers became a problem, and owners/managers found that they had to pay $8.00/$9.00/$10.00/hour to get them, at a time when the Federal minimum wage had not even yet reached $7.50/hour. Kids from affluent neighborhoods would not work in the fast food restaurants (such as McDonalds or Wendys) for less than $10.00/hour, while in poorer neighborhoods, they were glad to get minimum wage. There is a persistently shibboleth of conservatives that increasing the minimum wage will drastically increase prices, and the evidence simply doesn't support the claim. In fact, the evidence is, in the case of the already low minimum wages paid in this country, that increasing the minimum wage to more reasonable levels doesn't increase costs at all, although it certainly will reduce, but not significantly, the bottom line. So, the minimum wage is a huge political football, and for no very good reason.
Capitalist greed results in a lot of stupidity. If the United States were to become a Walmart nation, then before very long, the working class could not afford to shop anywhere else than Walmart. The greedy patricians of Rome destroyed the economy in the West with latifundia
, huge slave-driven enterprises, which destroyed the consumer class. When the empire ceased to expand, and actually began to contract, they no longer had buyers for their products, and debasement of the currency lead to run away inflation. The result was the collapse of the economy in the west, followed rapidly by the collapse of imperial authority. In the eastern portion of the empire, where those circumstances did not apply, the economy remained relatively healthy, a large consumer class remained, and imperial authority proved resilient. England ran into the same problem after 1815 when cheap American exports and higher quality French exports cut into their trade. Eventually, they discovered--to their horror--that the best way to assure higher productivity was to pay better wages, and to eliminate piece work and child labor. The American textile mills weren't bastions of enlightened labor relations, but they paid better wages, and were more productive. The French textile mills paid better wages (after 1830), and competed successfully on the basis of producing a higher quality product.
Most capitalists have very simple minded attitudes about costs and returns, and many people who are conservatives, but not capitalists, support their idiocy. The experience of centuries is that you do better in the long term by taking good care of your employees and relying upon higher productivity and better quality for sustained profitability. Most capitalists are not in it for the long term--they want quick, high profits, and damn the consequences.