So why did debt levels rise so dramatically after the final central bank restraint was removed? It is essentially due to the massive subsidy central bankers provided. If you tax a thing you get less of it (think all the tax on labour) but if you subsidise it you will get more of it. As time went by, debt obviously grew ever larger and eventually large enough to become an integral part of the business cycle. In other words, central banks could not stop the subsidy for fear of creating, well, a 2008 financial meltdown.