(apologies for not having time to write it concise and quickly to the point)
First off, Living Wage is marketing and political tripe. Just as we cannot set a nationwide minimum wage and expect it to serve people equally the same can be said about the $15 dollar value most associated with "Living Wage". Plus in some cities it comes with a collective bargaining exclusion which the unions want because they can then sell staff unionization to businesses under economic pressure.
So what happens if we reach this mythical living wage. Well most restaurants and big box stores, if not mom & pop businesses? The only flexibility is in wages. Everything else is basically locked in.
So now if wages go up a lot of people who used to be hired won't be. That neck and forearm tattooed person is of the list, same as the ones who sneaking food out but you overlook. Now your in the range of those who might be thinking they can make a career out of this at $15. There is a huge gap in who is employable at $9, $12, and $15. At the low end you can quit and probably get hired back when you need to bail a friend out. Businesses accept that level of worker at these pay points. Move up to $12 and even $15 and now, they don't get in the door. Suddenly at $15 jail time, drug use, and more, is not something you have to tolerate because you got people who will show up on time, dress right, and more, because they can make it work at $15
So the people who desperately need any job are out of consideration. They get pushed into the other market, day labor, prostitution, and fast money at worst. You end up with them hopefully on assistance programs because legal employment is basically out - they got priced out of the market.