Tools for Macro/Finance

By Lawrence J. Christiano




This is a graduate course on the basic tools for the rapidly growing field of Macro/Finance.  It is geared to students who will go on to do this type of work in their own research. For this reason, the course will not shy away from the technical details. At the same time there will be a constant focus on getting the intuition right.

Most of the models of finance that we will review in effect represent disturbances to the ‘intertemporal margin’.  In models with frictionless labor and goods markets financial frictions on the intertemporal margin tend to drive consumption and investment in opposite directions. But, macro data indicate that consumption and investment move in the same direction. For this and other reasons, we will use the New Keynesian model as our basic macroeconomic platform. For reasons we will see, this model has the advantage of predicting that consumption and labor move in the same direction. In recent years this model has also performed well on several other empirical dimensions: it predicted correctly that fiscal austerity slows down economic activity, rather than speed it up; it predicted correctly that the high money growth in recent years would be associated with low, rather than high inflation.

Next, we turn to models of financial frictions. I will organize the discussion around frictions on the liability and asset sides of financial firm balance sheets. Our analysis will help us in thinking about various problems in monetary policy: how monetary policy should respond to changes in interest rate spreads, what the effect of various types of unconventional monetary policy are, as well as macro prudential policy. A key feature of the Great Recession was the inability of the financial institutions in the shadow banking system to roll over their liabilities. Accordingly, the last lecture will discuss a model of a rollover crisis. In addition to exploring conceptual tools in macro/finance, students will also get some hands -on practice in the use of Dynare to solve and analyze dynamic models.



1) The New Keynesian (NK) model (handout, manuscript): basic principles and policy implications

a)  The version if the NK model that is described is inspired by recent improvements in understanding the network nature of actual production (Acemoglu, et al, 2015; see also). For example, networks can help provide an endogenous theory of price sluggishness through a strategic complementarity mechanism. They also convert the New Keynesian model into a quantitatively serious theory about the costs of inflation.

b)  Dynare code for solving and simulating the model in the handout, with some notes on the linearization strategy used by Dynare. A more rigorous treatment of the linearization solution strategy.

c)   Ramsey equilibrium.

d) Assignment #9, question 1, accomplishes two 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.

e)  For a version of the slides that goes into a detailed comparison of the New Keynesian and Real Business Cycle models, see handout.

f)    Other, related materials.

2) Financial frictions on the asset side of banks’ balance sheets.

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).

i)     A microeconomic approach.

Related empirical paper: Levin, Natalucci and Zakrajsek.

ii)  Introducing the frictions into a neoclassical growth model.

(1)                     Aggregation.

(2)                     The ‘financial friction wedge': very useful device for thinking about the dynamic effects of financial frictions.

b) Integrating CSV into a New Keynesian model and the results of Bayesian estimation of the model using US data (CMR, JMCB 2003AER 2014).

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.

3) Financial frictions on the liability side of banks’ balance sheets.

a)  Two-period exposition of Gertler-Karadi/Gertler-Kiyotaki model in which the financial frictions stem from bankers’ ability to ‘run away’ (section 3 of readinghandout).

b) Extending the analysis in (a) to multiperiods and to bank runs (‘rollover crises’), using Gertler-Kiyotaki AER2015 (for an informal discussion of the role of a rollover crisis in the Great Recession, see this and the references therein).

c)   Dynamic Model in which financial frictions stem from the fact that to do their job well, bankers must exert costly but unobserved effort. The environment has the implication that imposing leverage restrictions on banks can raise social welfare by addressing an externality. It thus provides a laboratory for thinking about macro prudential policy (background manuscript).

d) The reading also shows (in two-period settings) how financial frictions on the liability side of banks’ balance sheet can arise from adverse selection and costly state verification. We will not discuss these cases in the lectures.



Additional Background

Reference for New Keynesian models: Christiano, Trabandt and Walentin, Handbook of Monetary Economics, edited by Friedman and Woodford.

Interview on DSGE models.

General discussion of Great Recession and, among other things, role of rollover crisis.

More formal discussion of Great Recession in US: Christiano, Eichenbaum and Trabandt (AEJ-M 2015), ‘Understanding the Great Recession’.