Anything above median for your city is excess, anything under it is deficient. The question is at which point the excess should be taken, and the deficient subsidized. I'd roughly say 30% on either side of median.

However, not all that long ago, for ~40 years, the U.S. had a top tax bracket above 70%, for about a decade it was 94%. It was not such an exact system where to draw the line. But a line was drawn, and it was not 94% of all of your income, it was only the portion of your income that was above the previous bracket limit. It's not like you make $1 more and suddenly all your other income got hit with this much higher tax. So the fuck all for these hoarders. Start a new business, expand the current one, and you get a tax deduction. If you hoard, fuck you, we have ideas and ways to spend that money, we're taking it. Don't like it? Give up your citizenship. Go pay 70% in some other western civilized country. Or run for office and have your ideas dissected by the American public. Just quit your fucking bitching, whiners.

And meritocracy alone doesn't work. A lot of effective people are assholes who would let the world around the average person burn to the ground before they'd lift a finger. And even that would be delegated.