While some pundits claim the Fed's decision not to taper was driven by a myriad of factors — from Syria to the debt ceiling — the truth is far simpler than that: mortgages matter, according to an op-ed at the Milwaukee-Wisconsin Journal Sentinel:

There are hundreds of economic statistics that bear watching and most imply the recovery is continuing, albeit at glacial speed. Yet the rate on conventional 30-year mortgages is the one data point that may have cowed the Fed into waiting awhile longer before pulling back.

In a world of excess labor and productive capacity, economic growth is being driven by inflation in financial (equities and fixed-income) and real (housing) assets.

With real incomes stagnant, it's possible the Fed understands that much of the asset inflation we've seen in interest-rate dependent.