Financial frictions, business cycles and optimal monetary policy

Abstract

The great recession that started in 2007, has not only changed the perspective of the macroeconomic literature about the role of financial frictions within the canonical New Keynesian (henceforth, NK) monetary models but also has rekindled the debate about sources of business cycle fluctuations. This dissertation, comprising of three self-contained essays, makes theoretical and empirical contributions to the emerging strands of literature incorporating financial frictions in the NK monetary models. The first essay (Chapter 2) of this dissertation extends traditional optimal monetary policy analysis to NK models with capital and financial frictions. In the case of a negative productivity shock, the chapter finds that: 1) a standard inflation targeting rule dominates the Taylor rule in both NK models without capital and with capital as it approximates the welfare level associated with the Ramsey policy; 2) in the NK model with capital and with financial frictions, the relative performance of the economy under standard inflation targeting is much better compared to alternative policies because it approximates Ramsey monetary policy. In the case of a financial shock, the chapter shows that the inflation targeting rule provides a welfare level that is close to the welfare level achieved under optimal monetary policy under commitment. In addition, Ramsey policy under commitment performs well in response to a financial shock, compared to alternative monetary policy regimes, by aggressively minimizing the impact of financial constraints on the interest rate spread. The second essay (Chapter 3) estimates the importance of financial shocks in business cycle fluctuations for the US economy using structural VAR models. In that chapter, financial and non-financial shocks are identified with a minimum set of sign restrictions based on the two competing NK models: the standard NK model augmented with a financial accelerator and the NK model augmented with financial intermediaries. Estimation results show that a financial shock, emanating both from entrepreneur's net worth and financial intermediaries net worth, is prominent in explaining fluctuations in real output and interest rate spread. As far as the relative importance of these two financial shocks is concerned, the following results stand out. A financial shock related to the demand side is relatively the major driver of output fluctuations in both time horizons while financial shocks related to financial intermediaries explain a moderate variation in output fluctuations in both time horizons. In addition, financial shocks related to financial intermediaries account for a relatively larger share of interest rate spread fluctuations at both time horizons compared to a financial shock related to the demand side. The third essay (Chapter 4) extends Gertler and Karadi's model (2011) into a two-sector setting. The Two-Sector Financial Accelerator model not only helps to incorporate the differences in the leverage ratios of commercial and investment banks but also introduces additional shocks that capture some features of the sub-prime financial crisis in the simulated economy. The results also show that output recovery would remain slow in the simulated economy as long as the relative price of non-consumption goods is not recovered to its trend.