Yep, well structured argument. +1

One problem here is that luxury is personal & subjective. One person's luxury may be the conventional big cars & vacations in 5-star hotels, another's might be biking & sleeping in a tent.

I'd suggest that New Wealth are "management & co-ordination" of your Middle class. "build businesses, create jobs, meet demand" is reliant upon the consumption of the Middle and Poor. Proportioned to their income, they don't produce or consume as much as the Middle.

But I agree with the main point that how rich a country is, is basically how big the Middle class is compared to the Material Poor.

@Caleth, I had to simplify somewhere. Comparing individuals, the wealthy spend far more than the middle class ever can. Comparing classes, the middle class outspends the wealthy by leaps and bounds. Regrettably, the field of economics is complex in the best of times. It's tough hammering it down to the size SE wants to see in its answers.

@jamesqf, I kinda point that out a few times, perhaps most clearly when I say Remember that "wealth" isn't about money, it's about luxury, influence, and power. A shop keeper can be those things, so can an industry mogul. It wasn't a detail that needed focus, so I didn't take much time on it. You are, of course, absolutely correct.

The stats don't really back your assertion that the material poor donate less than the middle class. www150.statcan.gc.ca/n1/pub/71-542-x/2009001/c-g/ch1/… is a nice clear example, if anything lower income bands give more generously in both time and money

By the way: the minimum wage was not meant to "raise people out of poverty" (despite the advertisement thereof) but rather to "make labor more expensive and price the material and institutional poor out of the workplace." That is: labor becomes expensive requiring a higher skill ceiling for an employer to consider the employee "worth the expense." Few people ever think about the economics of labor and if you think about it for a minute, raising the cost of production by \$1 raises the sale price by at least \$1 and the majority of people paying are the ones at or near minimum wage...

@Clumsycat, that's a great chart, thanks!

@Draco18s, you're describing a consequence of minimum wage. I've never known anyone to use that issue as an argument in favor of minimum wage. However, I believe your explanation is a more precise statement of my point #2. Thanks for contributing!

I agree that wealth is the ability to command more resources, BUT I disagree that the working class is, by definition, the middle class. History has lots of counter-examples: Feudalistic states, colonialistic states, and state with a large slave caste (not all fit but many do).

@toolforger, none of those meet the OP's expectations. Remember, my answer is a simplification that challenges the OP's premise, not a general dissertation on labor, economics, and governing systems. Indeed, from this perspective, two of the four solutions offered in the accepted answer don't meet the OP's expectations either (gated nations/feudalism). Shifting the working class out of view doesn't minimize or rid society of the working class - but the OP is trying to somehow merge the working class and the wealthy. So, I get your point, but it's too general for the OP's specific needs.

@JBH Oh, its not meant to be an argument to be in favor of. Its merely the logical conclusion of what happens when the idea hits implementation. In theory, having a viable minimum wage is a good thing, the problem is that you also need to make sure that everyone is actually employed. But yes, I'm happy to help expand on your points. :)

@JBH I mentioned those old societies to refute your claim that any society must have a middle class to be economically viable. E.g. feudalism has been viable for more than a millenium. (If I wanted to claim that feudalism is an answer to the OP's question, I'd haven written an answer.)

@JBH Further, you present your answer as if it were based on common sense and sensible consensus, while in reality, many of your claims can be reasonably disagreed.

@toolforger, you're certainly welcome to write your own answer. That's the preferred solution on Stack Exchange so that the community can vote on your views.

@toolforger, I've had a bit more time to think about your statements. It's true that I have not provided an exhaustive list of classes. However, I believe you are certainly incorrect. There is always a middle class. Your tradesmen, shop keepers, landed gentry, etc. Even in feudalism, while the serfs worked, they were not at all the only working class. I'm not sure they were even the majority working class. Further, all slave-owning societies had non-slave-owning people who worked who outnumbered the slaves. I believe I'll stand by my assertion that there is always a middle class.

The argument lacks evidence, especially the percentages which appear fictional. It is an established fact that the poor give a greater proportion of their income to charity than the rich. It's also incomprehensible how a minority of homeless and chronically ill consume vast resources. Furthermore, the fundamental logic is unrealistic. Wealth is generated only by consumption/demand. No unwashed masses buying your stuff, no super rich guy being a '100%' producer. That wealth is owed to working consumers.

You've also created a paradox. If the ultra wealthy are 100% productive, how can you then say if everyone is made wealthy, they will be less productive? Either poverty motivates work, in which case the wealthiest are not productive, but parasitic, or wealth motivates everyone, and the poor are unproductive because they are deprived of incentive. You can't have it both ways, which is it?

@JBH you're thinking late dark ages, where a middle class had started to exist in towns, which wasn't feudalism anymore. Go back to Charlemagne, and that middle class becomes paper-thin, or even nonexistent because everybody is serf, travelling merchant, or nobility (senescals etc.).