Incomplete Markets, Transitory Shocks, and Welfare

Although equilibrium allocations in models with incomplete markets are generally not Pareto-efficient, it is often argued that quantitative welfare losses from missing assets are small when time horizons are long and shocks are transitory. In this paper we use a computational analysis to show that even in the simplest infinite horizon model without aggregate uncertainty welfare losses can be substantial. Furthermore we show that in this model welfare losses from incomplete markets do not necessarily disappear when one considers calibrations of the model in which agents become very patient. We argue that when the economic model is calibrated to higher frequency data, the period persistence of negative income shocks must increase as well. In this case the welfare loss of incomplete markets remains constant even as agents' rate of time preference tends to one. Journal of Economic Literature Classification Numbers: D52, D58, D60.     

Optimality and Natural Selection in Markets

We ask if natural selection in markets favors profit-maximizing firms and, if so, is there a difference between the predictions of models which assume all firms are profit maximizers and the predictions of models which explicitly take account of population dynamics in the market. We show that market selection favors profit maximizing firms, but we also show that the long-run behavior of evolutionary market models is nonetheless not consistent with equilibrium models based on the profit-maximization hypothesis. Dynamic equilibrium paths with market selection are not Pareto optimal, nor even asymptotically optimal. The discrepancy arises because the dynamics created by firm evolution causes prices to vary over time and the resulting dynamical system need not have stable steady states.     

Incomplete Markets, Allocative Efficiency, and the Information Revealed by Prices

We compare rational expectations equilibria with different degrees of information revelation through prices. These equilibria arise in a two-period exchange economy with finitely many states and signals, multiple commodities and incomplete financial markets for nominal assets. We show that there are always equilibria where information is redundant in the sense of being of no value to the uninformed traders. We give conditions under which for a generic set of economies, parametrized by endowments and utilities, there exist open sets of equilibria for which allocative and informational efficiency are independent, with implications for monetary policy. Journal of Economic Literature Classification Numbers: D52, D60, D82, E52.     

A Brief Overview of the Economics of Incomplete Markets

This paper was motivated by my participation in the Economic Theory Symposium of the 1988 Australian Economics Congress, Canberra. It represents only one perspective on an immense literature. As the reader will notice, I have often referred to my own work. for two reasons. The first is because it is what I know best, the second is to provide an illustration of the in efficiency resulting from the incentive constraints editors face in contracting for surveys .     

Macroeconomic Uncertainty,Fund Demand and Corporate Investment

Using a unique set of data on fund use by China’s listed companies, this paper examines how macroeconomic uncertainty works on corporate investment. The study shows that macroeconomic uncertainty affects corporate investment behavior through the three channels of external demand, liquidity demand and long-term fund demand. However, the result is influenced by expectations and can differ across firms depending on their economic cycle, shareholder character, industrial character and the financial constraints they are exposed to. Specifically, high macroeconomic uncertainty can weaken the positive roles of these channels, especially those of external demand and liquidity demand, in driving corporate investment. During economic upturns, the effect of these channels is the most evident among state-owned firms, manufacturing firms and low cash dividend firms. The lessons from this study are that macroeconomic policies should be leveraged taking account of the channels through which economic shocks find their way, and monetary policies have to be implemented by targeting microscopic fund demand.     

Duplicating and Pricing Contingent Claims in Incomplete Markets

The paper studies the problem of pricing contingent claims in the situation where the constraints imposed on an investor's portfolios are important. There are two types of rule of constraint: under a rigid rule, an investor must strictly limit his portfolios inside the constraint; under an elastic rule, an investor pays a penalty when the constraint is violated. The central problem of pricing a contingent claim is to determine the initial investment required to duplicate the contingent claim. The following results are obtained: (i) under elastic rules, the cost to duplicate a contingent claim exists and is unique;(ii) this cost depends nonlinearly and convexly on the contingent claim;(iii) the cost under rigid rules resulting from passing the penalty to infinity is also a nonlinear and convex function of the contingent claim. Owing to this nonlinearity, the cost of duplication may be or may not be the nonarbitrage price of the contingent claim; this depends on how the market organizes the production of contingent claims. The conclusion that the cost of duplication is a convex function of the contingent claim provides an explanation for why the service of providing contingent claims is often a highly profitable business. The main mathematical tool in the analysis is backward stochastic differential equations (BSDEs). In fact the cost to duplicate a contingent claim is the solution of a BSDE in which the contingent claim is the terminal value.     

Economic Uncertainty,Monetary Uncertainty,and the Demand for Money: Evidence From Asian Countries

In 1984 Nobel Lauriat Milton Friedman claimed that the decline in velocity of money or an increase in the demand for money was due to volatility of money supply. Another study argued that if monetary volatility could impact the demand for money, so can output volatility (as a measure of economic uncertainty). Both measures of uncertainty can cause people to reallocate their assets between cash and real assets that are less risky. If public become more cautious about the future, they will hold more cash today. However, if they chose to hedge against uncertain prices, they may hold more real assets and less cash. These two hypotheses are tested for Asian countries using bounds testing approach. While both measures are found to have short‐run significant effects on the demand for money in almost all countries, the short‐run effects last into the long run in half of the countries. Furthermore, we find positive and negative effects of both measures which are in line with previous research related to a few developed countries.     

Fiscal Policy with Heterogeneous Agents and Incomplete Markets

I undertake a quantitative investigation into the short run effects of changes in the timing of proportional income taxes for model economies in which heterogeneous households face a borrowing constraint. Temporary tax changes are found to have large real effects. In the benchmark model, a temporary tax cut increases aggregate consumption on impact by around 29 cents for every dollar of tax revenue lost. Comparing the benchmark incomplete-markets model to a complete-markets economy, income tax cuts provide a larger boost to consumption and a smaller investment stimulus when asset markets are incomplete.     

转轨经济中的信息、不确定性与贷款决策机制--一个将制度性信息内生化的贷款决策模型

文章在批判吸收相关文献合理成分的基础上,分析了贷款直接决策者所面临的包括制度性信息在内的各类信息及其不确定性,并且认为转轨经济中的贷款决策主要是贷款直接决策者在上述信息和不确定性的约束下,根据概然性的推断作出的.文章在对Heiner和Vercelli的模型进行必要的修正后,建立了一个含有制度性信息内生变量的、对转轨经济中的贷款决策行为具有较强解释力的、较为宽泛的理论模型,并据此阐释了在中国渐进式改革过程中的结构性信贷配给机制.     

An Incomplete Markets Explanation of the Uncovered Interest Rate Parity Puzzle

A large literature attributes failure of uncovered interest rate parity (UIP) to the existence of a time‐varying risk premium. This paper presents a mechanism in a simple two‐country two‐good endowment economy with incomplete markets that generates sizeable deviations from UIP. In a parameterization where international wealth effects are important, liquidity constraints on an internationally traded bond and agents’ strong resulting precautionary motives successfully generates a time‐varying risk premium: countries that have accumulated large outstanding external positions have, being closer to the constraints, stronger precautionary motives and their asset carries a risk premium.     

关于股票市场与货币需求增量关系的质疑

近年来,我国理论界普遍认为,股票市场的发展与扩张对货币产生了不可忽视的增量需求, 但是,在我国资本市场发展过程中所表现出来的这一现象却与国外在经济金融发展过程中所反映出来的一些普遍规律不尽相同.由于美国股市事实上已成为世界经济发展的晴雨表,故本文将借助对中国和美国股市在货币需求问题上的比较研究,以期更深刻地揭示资本市场发展对货币需求的影响以及其中的内在规律,并提出相应的政策建议.     

Uncertainty and Consumption in Keynes's Theory of Effective Demand

Keynesian uncertainty normally exercises influence over effective demand via private investment. This paper expands the scope of influence of uncertainty to comprise private consumption as well. When private spending is explicitly made subject to uncertainty the individual consumer is forced to take active steps to make the future predictable. Contracted, sticky money prices are key tools in the consumer's efforts to keep uncertainty at a minimum and match earnings with consumption costs. However, even if prices are successfully contracted there is still need for preparedness against contingencies. Consumers therefore regulate their propensity to consume with reference to their confidence in the future: the propensity to consume is high when confidence is strong and low when confidence is weak. Because of its effect on the propensity to consume, consumer confidence exercises a significant influence on macroeconomic activity in general.     

The Optimality of Competitive Air Transport Markets: A Review of Aspects of the ICAP Report*

The results of a model of optimal air fares and flight frequency, which can also be used to generate market results, are applied to market failure arguments, contained in the recent ICAP Report, for regulation of international airlines. The arguments of the report are classified under headings of capacity and utilization, ‘on-demand’ service and fare structure. It is argued contrary to the ICAP Report that the competitive result can he optimal in conditions likely to apply on international routes.     

Rationing rule, imperfect information and equilibrium

Summary. The impact of imperfect information on the price setting behaviour of firms is analysed. Specifically, consumers support an information cost to become informed about prices. Firms are endowed with U-shaped average cost curves. If a firm does not supply more than its competitive supply as determined by its marginal cost schedule, then we show that the existence of a pure strategy equilibrium is conditional on the rationing rule employed. If uninformed consumers are served first then the monopoly price is the sole equilibrium whenever consumers' information costs are high enough. Otherwise, a pure strategy equilibrium fails to exist contrary to the results of Salop and Stiglitz (1977) or Braverman (1980) who implicitly suppose that firms supply all the demand at a given price. Received: May 17, 1999; revised version: September 15, 2000     

Two-settlement Systems for Electricity Markets under Network Uncertainty and Market Power

We analyze welfare and distributional properties of a two-settlement system consisting of a spot market over a two-node network and a single energy forward contract. We formulate and analyze several models which simulate joint dispatch of energy and transmission resources coordinated by a system operator. The spot market is subject to network uncertainty, which we model as a random capacity derating of an important transmission line. Using a duopoly model, we show that even for small probabilities of congestion (derating), forward trading may be substantially reduced, and the market power mitigating effect of forward markets (as shown in Allaz and Vila 1993) may be nullified to a great extent. There is a spot transmission charge reflecting transportation costs from location of generation to a designated hub whose price is the underlying for the forward contract. This alleviates some of the incentive problems associated with the forward market in which spot-market trading is residual. We find that the reduction in forward trading is due to the segregation of the markets in the constrained state, and the absence of natural incentives for generators to commit to more aggressive behavior in the spot market (the strategic substitutes effect). In our analysis, we find that the standard assumption of no-arbitrage across forward and spot markets leads to very little contract coverage, even for the case with no congestion. We present an alternative view of the market where limited intertemporal arbitrage enables temporal price discrimination by competing duopolists. In this framework, we assume that all of the demand shows up in the forward market (or that the market is cleared against an accurate forecast of the demand), and the forward price is determined using a market clearing condition.     

市场需求不确定条件下产能过剩问题研究

在市场经济条件下,出现产能过剩是一种普遍经济现象.当产能过剩引致闲置成本时,企业的产量、产品价格和企业利润会受影响,但一定程度的产能过剩有利于需求的扩张,有益于社会福利的改善.当微观主体的经营处于硬约束或软约束状态时,政府对前者不应干预而应适当相助,对后者应加强宏观规制.     

Sustainability,Optimality, and Development Policy

Considering sustainability a matter of intergenerational welfare equity, this paper examines whether an optimal development path can also be sustainable. It argues that the general “zero‐net‐aggregate‐investment” condition for an optimal development path to be sustainable in the sense of the maximin criterion of intergenerational justice is too demanding to be practical, especially in the context of developing countries. It further argues that while the maximin criterion of sustainability may be appealing to the rich advanced industrial countries, for the poor developing countries it implies equalization of poverty across generations, and as such is too costly a moral obligation to be acceptable. The paper suggests that a compromise development policy that follows the optimal growth approach but adopts certain measures to mitigate both the intergenerational and intragenerational welfare inequalities may be more appropriate for these countries. Some of the principal elements of such a policy are highlighted.