$12,320 is $147,000 a year.  That is not rich. This is total bull.  

Spending is a horrible way of calculating this.  Every student with loans knows you can spend 50k a year easily without including food or anything else.  You don't have to be rich to have a mountain of spending debt either.  At all.  When did wealth turn from earning to spending?  There are rich people who do spend much money at all.  Are they poor?  What?

An interesting but misleading fact. The few on the "rich" side of that scale, probably own more than everyone on the left hand of the scale.

I know.  There is no way in the world that spending $147,000 a year would make you rich though.  I was in downtown Manhattan last weekend and I can tell you thats not rich by any standards. 

Wealth operates on a very, very different scale in downtown Manhattan compared to the rest of the US and the world for that matter. It may not make you rich compared to Manhattan, but it makes you a lot wealthier than the rest of the US and the world.

Truthfully - no. People at this income/spending scale in the US still get very generous tax breaks (they pay almost no federal income tax), receive subsidized health coverage through ACA, get access to food stamps and generally are able to spend this $110 on rent, Netflix, food or really whatever they like. Or they can save it.

Say what? That's SPENDING $40,150 to be able to spend that you must be making more.

I just ran the SNAP tool making $40,150 with 1000 a month rent and 400 utilities and didn't qualify in Indiana.  Where are you coming up with subsidized health care, no income tax, and food stamps.... I net less than 40,150 and owe income taxes and qualify (I'm pretty sure) for jack shit in the way of assistance.

This study is completely bogus half the people in the US make less then $30K a year that is nowhere near being middle class. So if not even half the people in the US are middle class its highly doubtful that half the word population is middle class or higher. My guess is that this study was paid for by some unphilanthorpic billionaire so that they feel better about hoarding all that wealth.

My fault, I wasn't clear enough in my post. I should have said anyone working for a wage paycheque. So this would exclude the professions you've listed, they're professionals and would fall in the Middle Class since they own their means of production. Although, if by some chance you have a doctor or a lawyer who is not in control of their own practice, but instead on a wage cheque, then they would be working class - but I have never heard of such a thing, at least not in Europe since the collapse of the second world.

To be fair, straight capitalism in the US has caused this country's richest class to grow and its middle class to shrink. If this number (in the OP) means anything (and it sounds like it is not very representative of the individual economies), it grew because of a communist country with a capitalist outlook: China.

A mix is probably best: socialism with capitalism for instance. Straight capitalism has led to a country with the most billionaires and a middle class that's been shrinking for 30 plus years while the lower class grows daily.