I wonder if there's something about culture and having basic survival needs met. Most economic models assume effectively unlimited long-term demand: as productivity grows and people in existing sectors are thrown out of work, they will find new things to do, and the people who have reaped the financial rewards of productivity growth will find things that they want to spend money on, creating new jobs for the previously unemployed. What if this doesn't happen? What if instead of using money as a means to an end, people use it as the end itself, effectively treating it as a scorecard to be maximized without spending it? And what if on the other end, instead of people finding new ways to obtain money, they opt out of the economy instead, creating alternate games (literally - video games are apparently the main extra-economic outlet) to play. With basic survival needs taken care of by parents, there's no forcing function that makes them participate in the economy. You'd get a reality that looks fairly similar to our actual reality, in Japan and increasingly in other developed areas of the globe.