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Theses Doctoral

Low Inflation: Potential Causes, Effects and Solutions

Cotton, Christopher David

My dissertation focuses upon low inflation. Many developed countries, especially Japan and the Eurozone, have recently experienced prolonged periods of below-target inflation. This has been blamed for many economic ills including worsening the Great Recession and generating a slow recovery, making monetary policy ineffective and leading to lower labor market flexibility. I study what has caused low inflation, its potential effects and how it could be prevented.
In Chapter 1, I look at how effective raising the inflation target would be in mitigating the problems of low inflation. Many economists have proposed raising the inflation target to reduce the probability of hitting the zero lower bound (ZLB). It is both widely assumed and a feature of standard models that raising the inflation target does not impact the equilibrium real rate. I demonstrate that once heterogeneity is introduced, raising the inflation target causes the equilibrium real rate to fall in the New Keynesian model. This implies that raising the inflation target will increase the nominal interest rate by less than expected and thus will be less effective in reducing the probability of hitting the ZLB. The channel is that a rise in the inflation target lowers the average markup by price rigidities and a fall in the average markup lowers the equilibrium real rate by household heterogeneity which could come from overlapping generations or idiosyncratic labor shocks. Raising the inflation target from 2% to 4% lowers the equilibrium real rate by 0.38 percentage points in my baseline calibration. I also analyse the optimal inflation level and provide empirical evidence in support of the model mechanism.
In Chapter 2, I study to what degree the recent fall in inflation can explain the rise in firm profitability which has been blamed for a rise in inequality. A theoretical relationship between inflation and profitability is known to exist. I investigate the degree to which the recent fall in inflation can explain the rise in firm profitability. My three primary findings are: 1. The negative relationship between inflation and profitability does not hinge upon the Calvo assumption. Raising inflation significantly lowers profitability under all common price rigidities. The relationship can actually be significantly stronger under menu costs. 2. A rise in the degree to which firms discount the future magnifies the effect; a rise in elasticity of substitution can increase or decrease the effect depending upon the price rigidity. 3. The profit share has risen by around 3.5p.p. since the 1990s. In a richer model with firm heterogeneity, the recent fall in inflation is estimated to explain 14% of the rise. This can increase to 29% if firms are allowed to discount the future by more in line with estimates from the finance literature. I also provide empirical evidence for the negative relationship between inflation and firm profits.
In Chapter 3, I examine whether behavioral features can help to explain why some countries have persistently experienced low inflation at the zero lower bound. Economists are keen to introduce behavioral assumptions into modern macroeconomic models. A popular framework for doing so is sparse dynamic programming, which assumes that agents partly base their expectations upon a default model which is typically the steady state. This means agents' expectations will be wrong if there are long-run deviations from the default model and assumes agents can compute the default. I introduce an alternative form of sparse dynamic programming which tackles these problems by allowing for long-run updating to the behavioral part of agents' expectations. I apply this to derive a long-run behavioral New Keynesian model. Within this model, fixed interest rates yield indeterminacy and the costs of remaining at the zero lower bound are unbounded. These results are very different to a behavioral New Keynesian model based upon standard sparse dynamic programming, which can yield determinacy under fixed interest rates and bounded costs of the zero lower bound.


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More About This Work

Academic Units
Thesis Advisors
Woodford, Michael
Ph.D., Columbia University
Published Here
April 24, 2019