The minimum wage only does anything when set above what the market was otherwise willing to pay. If set at or below what the market was willing to pay it is irrelevant and unnecessary.
In economic theory, any increase in price, given a fixed demand, will cause a decrease in the consumption of that product, which here is labor. This is as ironclad a rule as one can find in the field. Necessarily, then, artificially fixing the minimum wage above what the market was willing to pay will ALWAYS cause increases in unemployment. There are no exceptions.
This is masked by the fact that in many places the minimum wages are set below what was going to be paid anyway. People look at a high standard of living and confuse cause and effect.
I will add that in the United States part of our problem is the ignorance of large segments of our populace, which makes them worth less. Both in rural areas, and inner cities some 40% of the kids fail to graduate high school. The difference is that in rural areas there are a lot of opportunities for unskilled labor. This is much less true in cities, particularly when characterized by high crime rates.
To belabor the obvious, universal public education was a key socialist objective for much of the 19th century. They got it. Now many of the people who ought in theory to most benefit from it fail to appreciate it at all.