> Based on the normal distribution of worker skills there will aways be plenty of people earning just minimum wage

Why? Wasn't the wage you made supposed to be based on the value you added? Or has that argument gone out the window?

I really don't see any reason why there ought to be a normal distribution of wages. Also, the wages are not distributed that way at all, it's a power law distribution, relatively large numbers of people make little money and relatively few people an enormous amount.

> but you can't infer that far more people are earning $6/hour at a $6/hour minimum wage than would be earning that wage if no minimum wage existed.

Sure you can. That's unassailable logic. Every person earning minimum wage is a datapoint that you can use as evidence. How many people do you suppose are earning minimum wage right now?

> Such large scale market inefficiencies would not last for long.

In countries without minimum wage they last up to today, in countries with they lasted up to the moment that minimum wage was introduced.

> Surely some workers would be paid somewhat less without minimum wage, but surely more people would be employed, gaining skills and experience, etc.

Right. You mean "would be locked in to wages below subsistence level without much chance of improvement". Gaining skills and experience doing what? Flipping burgers? Checking out at the register?

> Who really knows what the impact of this would be on various industries over time.

Shareholder value would increase :)

> The modern world has done away with low skilled manufacturing jobs (which might have been the first run on a ladder to more skilled jobs) and replaced hundreds of thousands of workers with a far smaller number of robots.

You must live in a different world than the one where I live. Where I live we've outsourced those manufacturing jobs to places where there is no minimum wage and there is a disregard to job safety and public health. And in more than just a few cases where there is no age limit for full time work either.

> Imagine a world in which people could be hired for $2 per hour (where that's all their skills were worth).

Imagine a world in which people could be hired for $7 per hour (where that's all their skills were worth).

We already live in that world.

So firms do take advantage.

> Firms do not "take advantage" any more than workers do.

Right. Workers have yet to take advantage of their employers in a single instance, whereas employers have historically abused their workers routinely and still do so today in many places, and would do so in many more given the chance.

The worst thing a worker can do is to strike. And that is - in most places - a government protected right. Coincidentially, most of the places where you can't legally strike also don't have a minimum wage.

Really, I can see a lot of advantages to Capitalism but there are limits to what it can achieve and if it was a perfect system then we wouldn't need minimum wage, and we wouldn't need unions either. In the real world, unfortunately, we need both.

Capitalism is like democracy, it's not perfect but it seems to be the best we've got. Hopefully in the longer term it will turn out that we can and will do better.

Then, on top of all that there is one more factor. The minimum wage sets the base level for all other wages. There would be a tremendous knock-on effect from removing the minimum wage. When minimum wage was introduced everybody benefited (well, except for the highest segment, maybe).