[anovikov]

A class is not about what you can buy, or what people think of you. It is about SOURCE of your income, not where it ends up.

The concept of class was invented by Karl Marx, a person belongs to some class based on his/her relation to the means of production. There are 3 factors of production: labor, capital, and land (that final one is of much less importance now than it used to be in Marx's era, but still). So there are classes: middle class are those deriving their income from work (rent on their labor), rich deriving their income from capital, and aristocrates deriving their income from land (these are now extinct). Poor are those who don't have any means of production, so they depend on social transfers like foodstamps. Of course these sources can mix in a single person - like a coder who rents out spare bedroom on airbnb, or a top manager who has some stock of the company he runs in addition to salary and bonuses, and gets some dividends on it - but the largest one 'wins'.

Because the IRS collects sources of income of people (because they are differently taxed), and publishes summary of its results, it is possible to make a very precise picture of American class structure/thresholds of classes. It is just that nobody likes these results.

[clarkm]

> The concept of class was invented by Karl Marx, a person belongs to some class based on his/her relation to the means of production.

Please. Class and caste have been around since the dawn of civilization.