>>This is vitally important because it means it's impossible for a significant percentage of people to retire early unless the remaining workforce becomes correspondingly more productive<<
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>>Arguably, that is already happening even without additional early retirees, simply because the increased average life expectancy (and thus the time people spend in retirement). Effectively, everyone is already doing an early retirement, compared to people 50 years ago.<<
Obviously the remaining workforce has become, and continues to become, correspondingly more productive. If you need another example of this, see 2008-2012. We lost millions of workers from employment ranks, and our GDP is currently higher than its ever been. Sure, past performance is no guaranty of future results, but I and many others believe this trend will only increase in the future. Fewer workers will be producing even more.