Optimal monetary policy in an economy with incomplete markets and idiosyncratic risk

This study investigates an incomplete markets economy in which the saving behavior of a continuum of infinitely lived agents is influenced by precautionary saving motives and borrowing constraints. Agents can use two types of assets (interest bearing IOUS and money) to smooth consumption. Money is valued because of a timing friction in the bond market. In particular, the bond market closes before agents observe their idiosyncratic productivity shock. I find that the Friedman rule is not optimal for this economy. The results indicate that the optimal allocation has a rate of inflation of 10%, and a positive amount of private credit held by the government. A positive inflation rate transfers resources from agents with big endowments to those holding bonds which improves risk sharing, and therefore, welfare. However, for higher rates of inflation, agents economize on money holdings, offsetting the insurance effects, and causing a reduction in welfare. Furthermore, higher rates of inflation discourage agents from borrowing, and the endogenous lower bound on bond holdings is higher than the exogenous borrowing limit. High rates of inflation, therefore, exacerbate frictions in the bond market.     

Altruism, incomplete markets, and tax reform

We compute the welfare effects of different revenue-neutral tax reforms that eliminate capital income taxation in two general equilibrium models calibrated to the U.S. economy. In our dynastic model, the reform with the largest welfare gain is the one that eliminates all income taxation and increases the consumption tax to 35%; 75% of the population alive at the time of the reform benefit from it. Individuals use intervivos transfers and bequests to redistribute the long-run benefits. In a pure life-cycle economy that lacks this redistribution technology, we find that the same reform would benefit only 9% of the population.     

Robust effects of a debt-financed tax cut in an economy with incomplete markets

International Tax and Public Finance - We propose a two-period pure-exchange economy with spot and nominal security markets and a government that enacts a debt-financed tax cut in the first period...     

Unsecured credit markets are not insurance markets

We study the extent to which unsecured credit markets have altered the transmission of increased income risk to consumption variability over the past several decades. We find that unsecured credit markets pass through increased income risk to consumption, irrespective of bankruptcy policy and the information possessed by lenders. If risk sharing has indeed improved over this period, the reasons do not therefore lie in the unsecured credit market.     

Incomplete markets, labor supply and capital accumulation

Endogenous labor supply decisions are introduced in an equilibrium model of limited insurance against idiosyncratic shocks. Unlike in the standard case with exogenous labor (e.g. [Aiyagari, S.R., 1994. Uninsured idiosyncratic risk and aggregate saving. Quarterly Journal of Economics 109, 659-684; Huggett, M., 1997. The one-sector growth model with idiosyncratic shocks: steady states and dynamics. Journal of Monetary Economics 39, 385-403]), labor supply is likely to be lower than under complete markets. This is due to an ex post wealth effect on labor supply (rich productive agents work fewer hours) that runs counter the precautionary savings motive. As a result, equilibrium savings and output may be lower under incomplete markets. It is also found that long-run savings remain finite even when the interest rate equals the inverse of the discount factor.     

U.S. consumer bankruptcy choice: The importance of general equilibrium effects

We study the implications of U.S. personal bankruptcy rules for resource allocation and welfare. Our analysis shows that general equilibrium considerations along with bankruptcy chapter choice and production matter crucially for the effects of policy reform. Contrary to previous work, we find that completely eliminating bankruptcy provisions causes significant declines in output and welfare by reducing capital formation and labor input. Furthermore, subjecting Chapter 7 filers to means testing, as suggested by recent legislative proposals, would not improve upon current bankruptcy provisions and, at best, leave aggregate filings, output, and welfare unchanged. However, we do find that an alternative tightening of Chapter 7, in the form of lower asset exemptions, can increase economic efficiency.     

Default, insurance, and debt over the life-cycle

The widespread use of debt and default suggests that unsecured credit markets play an important role in consumption smoothing. In this paper, I address two previously unanswered questions. First, how does policy towards debt default affect the evolution of consumption and net worth over the life-cycle? Second, how does debt default policy interact with social insurance over the life-cycle? The findings are as follows. First, US default policy appears “lax”, in the sense that it creates severe credit constraints, especially for the young. Second, eliminating default will lower consumption inequality among the young, but will increase it among the old. Third, social insurance alters default risk and, in turn, loan pricing, and therefore matters for purely intertemporal smoothing.     

Comparing the performance of market-based and accounting-based bankruptcy prediction models

Recently developed corporate bankruptcy prediction models adopt a contingent claims valuation approach. However, despite their theoretical appeal, tests of their performance compared with traditional simple accounting-ratio-based approaches are limited in the literature. We find the two approaches capture different aspects of bankruptcy risk, and while there is little difference in their predictive ability in the UK, the z-score approach leads to significantly greater bank profitability in conditions of differential decision error costs and competitive pricing regime.     

Dynamic forecasting behavior by analysts: Theory and evidence

We develop a multi-period learning model to examine the relation between analysts’ forecasting behavior and their performance. In a competitive market for banking services, the surplus and the analyst's payoff, which is determined through bargaining, are convex in her reputation. The convexity of her payoff structure and the presence of employment risk lead to a U-shaped relation between the analyst's forecast boldness and prior performance and a positive relation between forecast boldness and experience. We find support for these predictions in our empirical analysis. Significant underperformers (outperformers) face higher (lower) employment risk and are more likely to issue bolder forecasts.     

Information provision in over-the-counter markets

This paper analyzes endogenous information provision and purchase in over-the-counter (OTC) markets. On the supply side the optimal strategy of an information provider consists of selling identical information to all OTC traders. On the demand side OTC traders have an incentive to buy information from the same provider. If the incumbent information provider charges not too high a price, then an entrant firm has no demand even though it offers less expensive information of the same quality. This paper provides a rationale for the high level of market power in the industry for financial market data and credit rating services as well as why institutional traders may have no demand for a finer rating system. In addition, this paper shows that it is welfare improving for the security issuer to pay for rating services rather than having OTC traders purchase costly rating reports.     

The safety first expected utility model: Experimental evidence and economic implications

Roy’s [Roy, A., 1952. Safety first and the holding of assets. Econometrica 20 (3), 431–449] safety first criterion advocates the minimization of the probability of outcomes below a certain “disaster” level. This paper examines safety first theoretically and experimentally. We find that safety first plays a crucial role in decision-making, inducing choices that cannot be explained by, and even contradict, risk-aversion, Prospect Theory, and loss-aversion in general. Yet, safety first alone cannot explain individual choice. Therefore, we propose an expected utility – safety first (EU–SF) model where decisions are made based on a weighted average of the safety first criterion and standard expected utility maximization. We experimentally estimate these relative weights, and discuss their economic implications.     

Monetary Policy with Heterogeneous and Misspecified Expectations

In the recent literature on monetary policy and learning, it has been suggested that private sector's expectations should play a role in the policy rule implemented by the central bank, as they could improve the ability of the policymaker to stabilize the economy. Private sector's expectations, in these studies, are often taken to be homogeneous and rational, at least in the limit of a learning process. In this paper, instead, we consider the case in which private agents are heterogeneous in their expectations formation mechanisms and hold heterogeneous expectations in equilibrium. We investigate the impact of this heterogeneity in expectations on central bank's policy implementation and on the ensuing economic outcomes, and the general result that emerges is that the central bank should disregard inaccurate private sector expectations and solely base its policy on the accurate ones.     

Taxes, transfers and employment in an incomplete markets model

The consequences of increases in the scale of tax and transfer programs are assessed in the context of a model with idiosyncratic productivity shocks and incomplete markets. The effects are contrasted with those obtained in a stand-in household model featuring no idiosyncratic shocks and complete markets. The main finding is that the impact on hours remains very large, but the welfare consequences are very different. The analysis also suggests that tax and transfer policies have large effects on average labor productivity via selection effects on employment.     

Anonymous markets and monetary trading

We study infinite-horizon monetary economies characterized by trading frictions that originate from random pairwise meetings, and commitment and enforcement limitations. We prove that introducing occasional trade in ‘centralized markets’ opens the door to an informal enforcement scheme that sustains a non-monetary efficient allocation. All is required is that trading partners be patient and their actions be observable. We then present a matching environment in which trade may occur in large markets and yet agents’ trading paths cross at most once. This allows the construction of models in which infinitely lived agents trade in competitive markets where money plays an essential role.     

Informed traders and limit order markets

We consider a dynamic limit order market in which traders optimally choose whether to acquire information about the asset and the type of order to submit. We numerically solve for the equilibrium and demonstrate that the market is a “volatility multiplier”: prices are more volatile than the fundamental value of the asset. This effect increases when the fundamental value has high volatility and with asymmetric information across traders. Changes in the microstructure noise are negatively correlated with changes in the estimated fundamental value, implying that asset betas estimated from high-frequency data will be incorrect.     

Multi-agent investment in incomplete markets

The problem of the expected utility maximization in incomplete markets for a single agent is well understood in a fairly general setting. This paper studies the problem for the multi-agent case. For this case a cooperative investment game is posed as follows: firstly collect all agents capital together at the initial time, then invest the total capital in a trading strategy, and finally divide the terminal wealth of the trading strategy and each of them gets a part. We give a characterization of Pareto optimal cooperative strategies and a characterization of situations where cooperation strictly Pareto dominates non cooperation, and prove that the core of the cooperative investment game is non-empty under mild conditions using Scarf theorem.Received: August 2003, Mathematics Subject Classification (1991): 91B28, 91A12, 60H30JEL Classification: G11, C71This work is supported by the National Natural Science Foundation of China under grant 10201031. It is a pleasure for the author to express his sincere thanks to an anonymous referee for valuable suggestions.     

Coherent hedging in incomplete markets

In incomplete financial markets, not every contingent claim can be perfectly replicated by a self-financing strategy. In this paper, we minimize the risk that the value of the hedging portfolio falls below the payoff of the claim at time T. We use a coherent risk measure, introduced by Artzner et al., to measure the risk of the shortfall. The dynamic optimization problem of finding a self-financing strategy that minimizes the coherent risk of the shortfall can be split into a static optimization problem and a representation problem. We will deduce necessary and sufficient optimality conditions for the static problem using convex duality methods. The solution of the static optimization problem turns out to be a randomized test with a typical 0–1 structure. Our results improve those obtained by Nakano. The optimal hedging strategy consists of superhedging a modified claim that is the product of the original payoff and the solution to the static problem.     

Inflation ambiguity and the term structure of U.S. Government bonds

Variations in trend inflation are the main driver for variations in the nominal yield curve. According to empirical data, investors observe a set of empirical models that could all have generated the time-series for trend inflation. This set has been large and volatile during the 1970s and early 1980s and small during the 1990s. I show that log utility together with Knightian uncertainty about trend inflation can explain the term premium in U.S. Treasury bonds. The equilibrium has two inflation premiums, an inflation risk premium and a Knightian inflation ambiguity premium.     

Consumption-portfolio optimization with recursive utility in incomplete markets

In an incomplete market, we study the optimal consumption-portfolio decision of an investor with recursive preferences of Epstein?CZin type. Applying a classical dynamic programming approach, we formulate the associated Hamilton?CJacobi?CBellman equation and provide a suitable verification theorem. The proof of this verification theorem is complicated by the fact that the Epstein?CZin aggregator is non-Lipschitz, so standard verification results (e.g. in Duffie and Epstein, Econometrica 60, 393?C394, 1992) are not applicable. We provide new explicit solutions to the Bellman equation with Epstein?CZin preferences in an incomplete market for non-unit elasticity of intertemporal substitution (EIS) and apply our verification result to prove that they solve the consumption-investment problem. We also compare our exact solutions to the Campbell?CShiller approximation and assess its accuracy.