I agree with this: as soon as the benefit of those last few percent is outweighed by the cost of achieving it, most people decide that's where they're going to call it quits. But I'm not sure that this is at odds with anything I said above: my big question is "What IS the benefit one gains from earning $1.8 million/year rather than $1.6 million/year?" From my perspective as an earner well below those rarefied heights, it naively seems like it would be a lot like getting those last few percent: nice and all, but maybe not worth losing more sleep. If a lot of people really do perceive that increase as a big deal, I'm very interested in knowing what they get out of it.