12 For a theoretical analysis of the fiscal and monetary policy mix at the ELB, see Woodford and Xie (2020), and for studies of the government expenditure multiplier at the ELB, see Woodford (2011); Christiano, Eichenbaum, and Rebelo (2011); and Eggertsson (2011).
The other challenge is that “we are making our way as we go”, because the crisis is not over yet, and we are working on the basis of preliminary lessons without being able to fully assess the likely consequences.