I only meant to say the majority of the middle class would fall under $120k no matter how you (reasonably) draw it (so with respect to that specific VAT/UBI pro

I only meant to say the majority of the middle class would fall under $120k no matter how you (reasonably) draw it (so with respect to that specific VAT/UBI proposal, most of the middle class would see a gain). For how higher incomes could end up middle class I wasn't thinking of a different threshold, but ways of defining social class that are more qualitative than quantitative. For example you could define middle class as people who live a modest lifestyle financed by selling their labor to a company, and upper class as people who can live off wealth. So someone from a wealthy family living off a trust fund and going to an elite graduate school might count as upper class despite being low or middle income, and an engineer making $120k in the bay area might still count as middle class that way. Defining it like that would probably produce a small upper class relative to the size of the middle class, but in historical societies where social class was a bigger issue what's considered upper class is usually a pretty small percent of the population, so it wouldn't seem too crazy to me to define it like that.