Evaluating Central Banks' Tool Kit: Past, Present, and Future∗ Eric Sims Jing Cynthia Wu Notre Dame and NBER Notre Dame and NBER First draft: February 28, 2019 Current draft: May 21, 2019 Abstract We develop a structural DSGE model to systematically study the principal tools of unconventional monetary policy { quantitative easing (QE), forward guidance, and negative interest rate policy (NIRP) { as well as the interactions between them. To generate the same output response, the requisite NIRP and forward guidance inter- ventions are twice as large as a conventional policy shock, which seems implausible in practice. In contrast, QE via an endogenous feedback rule can alleviate the constraints on conventional policy posed by the zero lower bound. Quantitatively, QE1-QE3 can account for two thirds of the observed decline in the \shadow" Federal Funds rate. In spite of its usefulness, QE does not come without cost. A large balance sheet has consequences for different normalization plans, the efficacy of NIRP, and the effective lower bound on the policy rate. Keywords: zero lower bound, unconventional monetary policy, quantitative easing, negative interest rate policy, forward guidance, quantitative tightening, DSGE, Great Recession, effective lower bound ∗We are grateful to Todd Clark, Drew Creal, and Rob Lester, as well as seminar participants at the Federal Reserve Banks of Dallas and Cleveland and the University of Wisconsin-Madison, for helpful comments. Correspondence:
[email protected],
[email protected]. 1 Introduction In response to the Financial Crisis and ensuing Great Recession of 2007-2009, the Fed and other central banks pushed policy rates to zero (or, in some cases, slightly below zero).