While "top quintile" might be a useful economic definition, it's not the dictionary definition, nor the one used by many Americans when discussing class (which has major social considerations, in addition to economic ones).

From Merriam-Webster: a social class occupying a position above the middle class and having the highest status in a society

Many of the HN regulars are upper income, but very few would qualify as upper class (most of us lack the political and social connections).

Sure it's objective in the mathematical sense, but if you have 2 kids and two people working with a combined income of 112k you'd be upper class? I feel like a better way of looking at it would be average household income/average area COL per person or something, right?

Additionally, if the wealth distribution curve for the country is basically a backwards "L" with the bend at the ~99th percentile, the difference between the 60th and 80th percentiles isn't really meaningful since the "upper class" is clearly the 99th percentile.

Edit: obviously there are also social caste connotations that used to be applied here too, but I'm only interested in the economic definition.

In a CNBC Millionaire Survey it can be observed that a majority of millionaires polled, representing the wealthiest 10 percent of Americans, described themselves as middle class (44%) or upper middle class (40%)... Estimates for the size of this group [upper class] commonly vary from 1% to 2%, while some surveys have indicated that as many as 6% of Americans identify as "upper class." https://en.wikipedia.org/wiki/American_upper_class

And on the contrary, (in an oldish article), 19% of Americans believe they are in the top 1% of income earners, and 20% more believe they will one day be [1].

1: http://www.nytimes.com/2003/01/12/opinion/the-triumph-of-hop...

That might well be accurate. Class and income are not the same thing. A college professor is upper class even if they don't make millions, because of connections and authority. Likewise, "a single-digit millionaire doesn't have effective access to the legal system."

It's important to use feelings to divide people into classes, because that's one easy way we can justify hatred and dehumanization for ourselves.