Monetary Policy Delegation, Contract Costs, and Contract Targets

We reconsider the optimal central banker contract derived in Walsh (1995). We show that if the government's objective function places weight (value) on the cost of the contract, then the optimal inflation contract does not completely neutralize the inflation bias. That is, a fraction of the inflation bias emerges in the resulting inflation rate after the central banker's monetary policy decision. Furthermore, the more concerned the government is about the cost of the contract or the less selfish (more benevolent) is the central banker, the smaller is the share of the inflation bias eliminated by the contract. No matter how concerned the government is about the cost of the contract or how unselfish (benevolent) the central banker is, the contract always reduces the inflationary bias by at least half. Finally, a central banker contract written in terms of output (i.e., incorporating an output target) can completely eradicate the inflationary bias, regardless of concerns about contract costs.

Asset Pricing with Heterogeneous Agents, Incomplete Markets and Trading Constraints

The consumption capital asset pricing model is the standard economic model used to capture stock market behavior. However, empirical tests have pointed out to its inability to account quantitatively for the high average rate of return and volatility of stocks over time for plausible parameter values. Recent research has suggested that the consumption of stockholders is more strongly correlated with the performance of the stock market than the consumption of non-stockholders. We model two types of agents, non-stockholders with standard preferences and stock holders with preferences that incorporate elements of the prospect theory developed by Kahneman and Tversky (1979). In addition to consumption, stockholders consider fluctuations in their financial wealth explicitly when making decisions. Data from the Panel Study of Income Dynamics are used to calibrate the labor income processes of the two types of agents. Each agent faces idiosyncratic shocks to his labor income as well as aggregate shocks to the per-share dividend but markets are incomplete and agents cannot hedge consumption risks completely. In addition, consumers face both borrowing and short-sale constraints. Our results show that in equilibrium, agents hold different portfolios. Our model is able to generate a time-varying risk premium of about 5.5% while maintaining a low risk free rate, thus suggesting a plausible explanation for the equity premium puzzle reported by Mehra and Prescott (1985).