In short, what the living wage is really about is not living standards, or economics, but morality. Its advocates refuse to come to terms with the fact that wages are market price–determined by supply and demand, the same as the price of oil, steel, corn, or coal. And it is for that reason, rather than the practical details, that the broader political movement of which the demand for a living wage is the leading edge is ultimately doomed to failure: For the amorality of the market economy is part of its essence, and cannot be legislated away.
If the world had an infinite number of detached single family homes in places with fresh water and secure food supplies and good weather, making things "fair" would be quite easy. We can certainly do better than we currently are, but the underlying reason things aren't fair is that nature doesn't offer fair.
I said the market system is amoral. We can't will it to do what we want. You can't force a job to suddenly create $20/hr of economic value by placing a mandatory $20/hr price on it. Basic mathematics doesn't allow that.
Even if it could, that value would be so enormous that there are simple economic constraints on what's possible in terms of remuneration. Lot's of people are allocated what are probably criminally small portions of the value they create.
For instance, if the sanitation engineers in a city disappeared, you wouldn't want to be in that city 3 months later. The city's streets would be filled with rotting garbage, and that would be the least of it's problems. Its grey- and black- water processing systems would be long since collapsed. And that city'd better hope that no industrial actors took the opportunity to dispense of troublesome pollutants despite the lack of a functioning sanitation system.
The thing is, despite the critical importance of the guys running our sanitation systems, and the enormous value the environment they maintain confers on us, in my own city, not one of them makes USD300 grand a year. (Or even USD200 grand. You get the idea.) A lot of civilization collapses without them, but they are still some of the lowest paid professionals in all of engineering.
All that's due to the same economic limitations that constrict remuneration for farmworkers. They are absolutely essential. They create enormous value. Unfortunately, the way the system is set up, there is not much in the way of resources to reward them.
We can discuss changing the system, but I doubt most people would like the outcome of that exercise. That would definitely go under "Be careful what you wish for."
My comment was written to elucidate why "value they create" is a useless sentiment. For example, none of the paintings in Louvre or whatever museum have any value to me. But they do to other people, so it would be impossible to have a consensus on "value". Some people like strawberries and would value them more than people who don't like strawberries.
The purpose of paying someone is to perform the desired work. The amount paid is the signal to the person performing the work that the work you want to be done should be done rather than someone else's.
The purpose of paying someone is not to provide them with some nebulous concept of value or to make sure they have a minimum standard of housing and fed, etc. Those goals should be accomplished by other means (UBI or some other type of societal welfare system).
Our form of greed-centered capitalism is not some inevitable natural truth. We've chosen to live that way. We can choose otherways. We can choose to pay people to recognize their contributions to society, as opposed to how much they do to enrich an individual. We can choose to ensure everybody has decent living conditions, no matter what to do. We can choose to live vast swaths of humanity in dirt and squalor. We can choose to commit collective suicide.
It's up to us. Right now? It's a point where events are pushing us to consider our choices.
You have yet to provide a formula with which to calculate this amount. And since it's such a complicated concept, I'm going to go ahead and assume it's impossible to calculate.
We can choose some things, but not how a free market behaves. And experiments in non-free markets have not gone so well (see Chile, Venezuela etc etc).
Like it or not, I don't think I have this wrong. Wishing isn't the same as logic.
From there, we get to "would you die without them? If yes, maybe they're underpaid. Maybe $18K a year just isn't fair pay under any circumstances, not if we can't force people via a "well, you could always die" clause.
As for the value they create - you have food available to you. How valuable is that to you? Would you like it if farm workers applied the "well, you could always die or do it yourself" clause?
Because at some point, that becomes an option.
I understand what you're saying, my intention is to display how easy it is to say, but how difficult it is to execute. Currently, we pay people what it costs to replace them, but it would be nice if we could snap our fingers and give everyone a global standard of living equal to whatever the top 5% live in. Unfortunately, that's not possible, and short of a country wide or world wide effort to implement some type of UBI, I don't see much chance of success.
That's OK, I'm happy to help you with regulation.