Wealth inequality did this. It would have happened with or without the fed. As long as r > g the problem will only get worse.
If the US returned to a 1950s style tax system or enacted very high wealth taxes this problem could be avoided, but the forces arrayed against you for proposing such reforms would mean political suicide for anyone who does it.
Which makes me think that the problem will get worse until some sort of structural break occurs (at which point, as with 2008, it'll probably get worse at an accelerated rate with a cure worse than the disease).
If the US returned to a 1950s style tax system or enacted very high wealth taxes this problem could be avoided, but the forces arrayed against you for proposing such reforms would mean political suicide for anyone who does it.
Which makes me think that the problem will get worse until some sort of structural break occurs (at which point, as with 2008, it'll probably get worse at an accelerated rate with a cure worse than the disease).