With debt to GDP ratios at all time highs around the world we do seem to have reached (4). But money markets aren't free markets, being effectively controlled -

With debt to GDP ratios at all time highs around the world we do seem to have reached (4). But money markets aren't free markets, being effectively controlled - and distorted - by central banks. They hold interest rates low to attempt to spur investment in productive capacity. But business investments are motivated not only by interest rates (and labor market "flexibility") but by perceived demand, which, in part due to aforementioned low wage growth, stays weak. Capital and debt flows instead to bidding up asset prices.