i think it matters a lot. every few thousand you move that line in either direction is going to make a large direct impact on the apparent 'growth' or 'decline' on either side of it.

The only number that actually matters here is "median household income". The distance away on both sides doesn't matter, because the article is analyzing movement away from the center.

Does it matter if you're capturing the middle 20% or the middle 60% of the country? Not really. There are fewer people in the "middle", for some definition of middle.

> Does it matter if you're capturing the middle 20% or the middle 60% of the country? Not really.

Its actually capturing a multiplier below and above the median. If it was capturing a fixed percentage in the middle, then the share in the "middle class" could not change over time...

Lol, good point. But you'd be able to see the income spread of the middle class.

Its the spread that matters, and holding the income multiplier steady and then looking at %...

Or holding the % steady (then looking at the income numbers)...

That doesn't matter. Really. They all measure the spread away from the median over time.