New Keynesian DSGE Models, Financial Frictions and Bayesian Estimation
By Lawrence J. Christiano
This is a graduate-level course on tools for macroeconomics. It is geared to people interested in applying the tools in situations not necessarily considered previously in the literature. For this reason, the course will not shy away from the technical details. At the same time, there will be a constant focus on the intuition.
We begin by describing the basic New Keynesian closed economy model with no capital. The simplicity of this model will allow us to highlight core principles that apply more generally across models with price-setting frictions. It will also allow us to focus on a core technical problem in the New Keynesian model, how to aggregate across heterogeneous firms.
We then turn to a discussion of the econometric tools for estimating dynamic, stochastic, general equilibrium models like the New Keynesian model.
Next we extend the NK model into an open economy setting. We discuss properties of the model, its limitations, as well as problems (e.g., the UIP puzzle) which have been the focus of open economy macro for a long time and which still resist a satisfactory solution.
Finally, we consider financial frictions. We will examine in detail the consequences of incorporating financial frictions on the asset side of banks’ balance sheets. We will also discuss, at a more informal level, financial frictions on the liability side of banks’ balance sheets.
Computer exercises will give students hands-on practice in the use of Dynare to solve, estimate and analyze dynamic models.
1) The simple New Keynesian (NK) lecture 1 and lecture 2 on model without capital (background: my handbook chapter, and this comment on Acemoglu, et al, Macro Annual, 2015). We will stress the key role in short term economic dynamics of aggregate demand, and the importance of good policy for guiding it. We will evaluate inflation targeting from this point of view
b) Derivation of linearized NK Phillips curve.
c) Assignment #9, question 1, accomplishes three things.
i) Gives students experience with Dynare for solving and simulating models.
ii) Gets to the heart of the New Keynesian models by exploring its basic underlying economic principles.
iii) Shows how ‘news’ shocks might cause an inflation targeter to drive the interest rate in the ‘wrong’ direction and inadvertently trigger an inefficient stock market boom (Slides, manuscript; and section 3.2 of handbook chapter.)
d) Other, related materials.
a) State space representation of a model.
b) Elements of Bayesian inference (Bayes’ rule, MCMC algorithm).
c) A simple example to illustrate Bayes’ rule.
d) Assignment #9, questions after 1.
a) Micro foundations for the Costly State Verification (CSV) approach (zip file with code for the computations, and a version of the slides with more extensive derivations). The CSV model is used as a friction on the asset side of a bank’s balance sheet.
i) The model.
ii) The importance of risk shocks and news on risk.
iii) The response of monetary policy to an increase in interest rate spreads.
iv) Carefully documented (thanks to Ben Johannsen) Dynare code for replicating the material in this presentation.
c) Financial frictions on the liability side of banks’ balance sheet. Two-period exposition of Gertler-Karadi/Gertler-Kiyotaki model in which the financial frictions stem from bankers’ ability to ‘run away’ (section 3 of reading, handout).