In light of the recent monetary/fiscal policy debate, here's an excerpt of my take from the end of November on monetary offset in the context of the Taper on Quartz:
In its recent minutes, it appears that the US Federal Reserve has been preparing to taper. Yet given the outsize role the Fed has played in supporting the recovery, that would almost certainly be a mistake. Unemployment has been ticking down, yet long-term unemployment is still very high and labor force participation is still low. While the recovery has made progress, it is still not guaranteed, and the Fed’s accommodation will be critical if the economy is to secure the gains it has made.
The key to understanding the argument is to understand a concept central to economic analysis: the counterfactual. Counterfactuals are alternative histories of what could have been. In military history they are the answers to questions like “What would have happened if Napoleon had won the battle of Waterloo?” In this case, the key counterfactual is “What would have happened to the economy if the Fed hadn’t done quantitative easing?” Throughout this recovery, the federal government has been tightening its belt. Indeed, as MKM Partners chief economist Michael Darda has repeatedly noted, net government outlays have fallen for two consecutive quarters during this recovery, making the recent bout of austerity the biggest since the Korean War demobilization. Had the Fed not offset such a large contraction in spending, the US almost certainly would have been sent into another recession.