Time-varying risk, interest rates and exchange rates in general equilibrium
Time-varying risk is the primary force driving nominal interest rate differentials on currency-denominated bonds. This finding is an immediate implication of the fact that exchange rates are roughly random walks. We show that a general equilibrium monetary model with an endogenous source of risk variation?a variable degree of asset market segmentation?can produce key features of actual interest rates and exchange rates. The endogenous segmentation arises from a fixed cost for agents to exchange money for assets. As inflation varies, the benefit of asset market participation varies, and that ...
A Parsimonious Behavioral SEIR Model of the 2020 COVID Epidemic in the United States and the United Kingdom
I present a behavioral epidemiological model of the evolution of the COVID epidemic in the United States and the United Kingdom over the past 12 months. The model includes the introduction of a new, more contagious variant in the UK in early fall and the US in mid December. The model is behavioral in that activity, and thus transmission, responds endogenously to the daily death rate. I show that with only seasonal variation in the transmission rate and pandemic fatigue modeled as a one-time reduction in the semi-elasticity of the transmission rate to the daily death rate late in the year, the ...
Aggregate implications of innovation policy
In this paper we present a tractable model of innovating firms and the aggregate economy that we use to assess quantitatively the link between the responses of firms to changes in innovation policy and the impact of those policy changes on aggregate output and welfare. We show that, to a first-order approximation, a wide range of policy changes have a long-run impact in direct proportion to the fiscal expenditures on those policies, and that to evaluate the aggregate impact of a policy change, there is no need to calculate changes in firms' decisions in response to these policy changes. ; We ...
The optimal degree of discretion in monetary policy
How much discretion is it optimal to give the monetary authority in setting its policy? We analyze this mechanism design question in an economy with an agreed-upon social welfare function that depends on the randomly fluctuating state of the economy. The monetary authority has private information about that state. In the model, well-designed rules trade off society's desire to give the monetary authority flexibility to react to its private information against society's need to guard against the standard time inconsistency problem arising from the temptation to stimulate the economy with ...
The advantage of transparency in monetary policy instruments
Monetary policy instruments differ in tightness - how closely they are linked to inflation - and transparency - how easily they can be monitored. Tightness is always desirable in a monetary policy instrument; when is transparency? When a government cannot commit to follow a given policy. We apply this argument to a classic question: Is the exchange rate or the money growth rate the better monetary policy instrument? We show that if the instruments are equally tight and a government cannot commit to a policy, then the exchange rate's greater transparency gives it an advantage as a monetary ...
The balance of payments and borrowing constraints: an alternative view of the Mexican crisis
In this paper we develop a model in which a country faces a balance of payments crisis if constraints on its international borrowing bind. We use the model to describe the dynamics of the trade balance, capital account, and balance of payments of a country that borrows to finance consumption following sweeping macroeconomic and structural reforms and then hits constraints on its international borrowing. We compare the predictions of this theoretical example with events in Mexico from 1987 through 1995.
Deflation and depression: is there an empirical link?
Are deflation and depression empirically linked? No, concludes a broad historical study of inflation and real output growth rates. Deflation and depression do seem to have been linked during the 1930s. But in the rest of the data for 17 countries and more than 100 years, there is virtually no evidence of such a link.
The Risk of Becoming Risk Averse: A Model of Asset Pricing and Trade Volumes
We develop a new general equilibrium model of asset pricing and asset trading volume in which agents? motivations to trade arise due to uninsurable idiosyncratic shocks to agents? risk tolerance. In response to these shocks, agents trade to rebalance their portfolios between risky and riskless assets. We study a positive question ? When does trade volume become a pricing factor? ? and a normative question ? What is the impact of Tobin taxes on asset trading on welfare? In our model, economies in which marketwide risk tolerance is negatively correlated with trade volume have a higher risk ...
On the optimal choice of a monetary policy instrument
The optimal choice of a monetary policy instrument depends on how tight and transparent the available instruments are and on whether policymakers can commit to future policies. Tightness is always desirable; transparency is only if policymakers cannot commit. Interest rates, which can be made endogenously tight, have a natural advantage over money growth and exchange rates, which cannot. As prices, interest and exchange rates are more transparent than money growth. All else equal, the best instrument is interest rates and the next-best, exchange rates. These findings are consistent with the ...
External and Public Debt Crises
The recent debt crises in Europe and the U.S. states feature similar sharp increases in spreads on government debt but also show important differences. In Europe, the crisis occurred at high government indebtedness levels and had spillovers to the private sector. In the United States, state government indebtedness was low, and the crisis had no spillovers to the private sector. We show theoretically and empirically that these different debt experiences result from the interplay between differences in the ability of governments to interfere in private external debt contracts and differences in ...