When it became clear to investors that these alternative protections might not be adequate to protect against losses, widespread flight from the shadow banking system occurred, with pernicious dynamics reminiscent of the banking panics of an earlier era.
This gives some support to the second possible reading of the above chart. Under this interpretation, it would be overly optimistic to simply extrapolate the past growth trend into the future. On the contrary, we should consider the possibility that the Great Recession has marked the beginning of a new era of lower trend growth rates.