Voting in assemblies of shareholders and incomplete markets

Summary. An economy with two dates is considered, one state at the first date and a finite number of states at the last date. Shareholders determine production plans by voting - one share, one vote - and at -majority stable stock market equilibria, alternative production plans are supported by at most percent of the shareholders. It is shown that a -majority stable stock market equilibrium exists if where S is the number of states at the last date and J is the number of firms. Moreover, an example shows that -majority stable stock market equilibria need not exist for smaller s.Received: 23 December 2002, Revised: 14 June 2004, JEL Classification Numbers: D21, D52, D71, G39. Correspondence to: Hervé CrésThe authors are grateful to an anonymous referee for helpful comments and suggestions. Financial support from the Danish Research Councils and hospitality of HEC is gratefully acknowledged by Mich Tvede and support from Fondation HEC is gratefully acknowledged by Hervé Crés.     

A model for international capital markets closure in an economy with incomplete markets and short sales

Using a two-country dynamic optimization model, we investigate the impact of exchange risk, incomplete information and short sales constraints on international portfolio decisions around market closure. Using optimal control theory, we provide solutions and simulation results. Our model can be applied to solve several problems in financial economics in the presence of market closure, information asymmetry and short sales constraints.     

Stochastic equilibria with incomplete financial markets

We demonstrate the existence of equilibria with incomplete financial markets for stochastic economies whose information structure is given by an event tree, restricting attention to purely financial securities, those paying in units of account (e.g., “dollars”). Financial markets may be incomplete: some consumption streams may be impossible to obtain by any trading strategy. Securities may be individually precluded from trade at arbitrary states and dates. Sufficient conditions for the existence of stochastic equilibria are: continuous, convex, strictly monotonic preferences and strictly positive aggregate endowments. These conditions are weakened. A corollary states that any regime of security prices precluding arbitrage can be embedded in an equilibrium.     

Endogenous trading constraints with incomplete asset markets

This paper endogenizes the borrowing constraints on capital in a production economy with incomplete markets. We find that these limits get looser with income, a property that is consistent with US data on credit limits. The framework with endogenous limits is then used to study the effects of a revenue neutral tax reform that eliminates capital income taxes. Our results illustrate that it is very important to take into account the effects of tax policies on the limits. Throughout the transition, these effects can be big enough to change the overall conclusion about the desirability of a tax reform.     

Complete and incomplete markets with short-sale constraints

Summary. This paper argues that the introduction of a short-sale constraint in the Arrow-Radner framework invalidates standard definitions of complete and incomplete markets. Two threshold values with familiar properties arise in this constrained set-up. If short sales are not allowed on some security, then financial markets will be incomplete in the standard sense. Beyond a particular level of the short-sale bound, financial markets are “complete”, since the short-sale constraint is not effective. For intermediate bounds the distinction between complete and incomplete financial markets is blurred. Although some technical definitions hold, agents can not fully transfer wealth among states. These intermediate cases, called “technically incomplete markets”, exhibit interesting welfare properties. For instance, the resulting equilibrium allocations may not be Pareto-dominated by those of the non-restricted complete markets equilibrium. Received: November 28, 2000; / revised version: November 9, 2001     

Optimal taxation with endogenously incomplete debt markets

Empirical analyses of labor tax and public debt processes provide prima facie evidence for imperfect government insurance. This paper considers a model in which the government's inability to commit to future policies or to report truthfully its spending needs renders government debt markets endogenously incomplete. A method for solving for optimal fiscal policy under these constraints is developed. Such policy is found to be intermediate between that implied by the complete insurance (Ramsey) model and a model with exogenously incomplete debt markets. In contrast to optimal Ramsey policy, optimal policy in this model is consistent with a variety of stylized fiscal policy facts such as the high persistence of labor tax rates and debt levels and the positive covariance between government spending and the value of government debt sales.     

Equilibrium in economies with incomplete financial markets

This paper analyses an exchange economy in the absence of Arrow-Debreu complete markets. It is assumed that trading takes place in the sequence of spot markets and futures markets for securities payable in units of account. Unlimited short-selling in securities is allowed. A general equilibrium in such an economy is a set of current and future prices (contingent on uncertain events) and a set of individual plans such that all markets are cleared. The existence of such an equilibrium is proved under usual assumptions. This is in contrast to the case of futures markets for contingent futures commodities where an equilibrium may not exist. The optimality of equilibrium allocations is also discussed.     

On constrained optimal allocations with incomplete markets

Summary We provide an example of an economy with incomplete asset markets in which there is no constrained optimal allocation.I would like to thank Ramon Marimon for many helpful discussions, and to an anonymous referee for useful comments.     

Asymmetric information in bilateral trade and in markets: An inversion result

I consider bilateral trade between a seller and a buyer with private valuations. The seller makes a take-it-or-leave-it price offer. If the seller observes the buyer?s valuation (symmetric information), bilateral trade is trivially efficient. If the seller cannot observe the valuation (asymmetric information), bilateral trade is inefficient. This bilateral trading game is embedded into a large matching market. In the steady-state equilibrium of the market game, the relation between the informational regime and efficiency is inverted: With small frictions efficiency obtains if information is asymmetric. If information is symmetric, however, the trading outcome can be very inefficient—even if frictions vanish.     

A model of insurance markets with incomplete information

The paper investigates how a competitive market would allocate insurance policies if firms were not able to determine the riskiness of individual consumers. It is demonstrated that if all firms have static expectations with regard to the policy offers of other firms, no stationary equilibrium may exist. A second equilibrium concept is then introduced which incorporates a different expectation rule. Each firm assumes that any policy will be immediately withdrawn which becomes unprofitable after that firm makes its own policy offer. This equilibrium is shown to exist and some of its welfare properties are investigated.     

Futures markets and commodity options: Hedging and optimality in incomplete markets

This paper examines the allocational roles of futures markets and commodity options in multi-good and multi-period economies. In a continuous-time model with time-additive utilities and homogeneous beliefs, trading in “unconditional” futures contracts, the market portfolio and a riskless asset gives any Pareto-optimal allocation. Individuals' optimal holdings of futures contracts in the continuous-time model are related to their consumption bundles and to their risk tolerances. It is shown that both hedging and “reverse hedging” behavior are possible. In the general model with discrete trading, options on portfolios of commodity options are shown to permit any unconstrained Pareto-optimal allocation.     

An analysis of the conditions for the validity of Modigliani-Miller Theorem with incomplete markets

Summary In this paper we investigate the consequences of the firms' financial decisions in the framework of a perfectly competitive general equilibrium model with incomplete markets. When markets are complete or there are no derivative securities (such as options, forwards or futures) written on the firms' shares, these decisions are irrelevant. This result reaffirms and qualifies the original claim by Modigliani and Miller. On the other hand, if markets are incomplete, we show that in the presence of any type of derivative security a change in the capital structure of a firm will modify, generically, both the real equilibrium allocation and the value of the firm. The reason is that the payoff of the derivative securities is affected in a non-linear way by changes in the firm's financial policy; thus the set of the agents' insurance opportunities is also modified.The paper is a revised version of chapter 1 of my Ph.D. dissertation at Cambridge University. I wish to thank F. H. Hahn and H. M. Polemarchakis for their encouragement and very useful discussions. I am also grateful to J. Detemple, S. E. Satchell, S. Schaefer, P. Siconolfi, R. Stapleton, M. Subrahmanyam and three anonymous referees, as well as to participants at seminars at Cambridge, Columbia, EUI, Bocconi, USC, the R.E.S. Conference in Nottingham and the 6th World Congress of the Econometric Society in Barcelona for helpful comments. The usual disclaimer applies.     

Recursive equilibrium in endogenous growth models with incomplete markets

This paper analyzes the existence of recursive equilibria in a class of convex growth models with incomplete markets. Households have identical CRRA-preferences, production displays constant returns to scale with respect to physical and human capital, and all markets are competitive. There are aggregate productivity shocks that affect aggregate returns to physical and human capital investment (stock returns and wages), and there are idiosyncratic shocks to human capital (idiosyncratic depreciation shocks) that only affect individual human capital returns. Aggregate and idiosyncratic shocks follow a joint Markov process. Conditional on the aggregate state, idiosyncratic shocks are independently distributed over time and identically distributed across households. Finally, households have the opportunity to trade assets in zero net supply with payoffs that depend on the aggregate shock, but markets are incomplete in the sense that there are no assets with payoffs depending on idiosyncratic shocks. It is shown that there exists a recursive equilibrium for which equilibrium prices (returns) only depend on the exogenous aggregate shock variable (the wealth distribution is not a relevant state variable). Moreover, the allocation associated with this recursive equilibrium is identical to the equilibrium allocation of an economy in which households live in autarky and face both aggregate and idiosyncratic risk.I would like to thank for helpful comments Peter Howitt, Bob Lucas, Michael Magill, Tomo Nakajima, Herakles Polemarchakis, Martine Quinzii, Kevin Reffett, an anonymous referee, and seminar participants at various universities and conferences.     

Sunspots and incomplete financial markets: The general case

Summary This paper examines the effects of extrinsic uncertainty or sunspots on competitive equilibrium when financial markets are incomplete. For the canonical two-period, pure-exchange model with bonds (or so-called nominal assets, yielding fixed overall returns specified in units of account, and including pure inside money), the following result is established: Generically in endowments, if there areS sunspot states in the second period, but only 0<I<S distinct types of bonds, then — corresponding to the inherent deficiency in the financial markets — sunspots will generateD=S–I dimensions of consumption allocation or real (as well as spot price or nominal) indeterminacy.     

Equilibria in incomplete assets economies with infinite dimensional spot markets

The paper studies the two period incomplete markets model where assets are claims on state contingent commodity bundles and there are no bounds on portfolio trading. The important results on the existence of equilibrium in this model assume that there is a finite number of commodities traded in each spot market and that preferences are given by smooth utility functions. With these assumptions an equilibrium exists outside an “exceptional” set of assets structures and initial endowments. The present paper extends these results by allowing for general infinite dimensional commodity spaces in each spot market. These include all the important commodity spaces studied in the literature on the existence of Walrasian equilibrium—in each spot market the consumption sets are the positive cone of an arbitrary locally solid Riesz space or of an ordered topological vector space with order unit or of a locally solid Riesz space with quasi-interior point. The paper establishes that even with our very general commodity spaces there exists an equilibrium for a “very” dense set of assets structures. Our approach is in the main convex analytic and the results do not require that preferences be smooth or complete or transitive. The concepts and techniques studied in this paper have important finite as well as infinite dimensional applications. This paper has benefited from the comments of Martine Quinzii, Wayne Shafer, Manuel Santos and Yeneng Sun. The research of C. D. Aliprantis is supported by the NSF Grants SES-0128039, DMS-0437210, and ACI-0325846. The research of R. Tourky is funded by the Australian Research Council Grant A00103450.     

Strategic market games with a finite horizon and incomplete markets

Summary. We study a strategic market game associated to an intertemporal economy with a finite horizon and incomplete markets. We demonstrate that generically, for any finite number of players, every sequentially strictly individually rational and default-free stream of allocations can be approximated by a full subgame-perfect equilibrium. As a consequence, imperfect competition may Pareto-dominate perfect competition when markets are incomplete. Moreover - and this contrasts with the main message conveyed by the market games literature - there exists a large open set of initial endowments for which full subgame-perfect equilibria do not converge to -efficient allocations when the number of players tends to infinity. Finally, strategic speculative bubbles may survive at full subgame-perfect equilibria.Received: 24 January 2002, Revised: 21 February 2003, JEL Classification Numbers: C72, D43, D52. Correspondence to: Gaël GiraudWe thank Tim Van Zandt for his comments.     

Rigid labour markets with trade and capital mobility: theory and evidence

Abstract We develop a multi‐country model with imperfect labour markets to study the effect of labour market frictions on bilateral trade flows. We use a framework that allows for goods trade and capital mobility and show that labour market imperfections exert opposite effects in the absence of capital mobility (the short run) and its presence (the long run), respectively. In the short run, a higher degree of labour market rigidity decreases the value of total trade, but increases the share of intra‐industry trade for a country that is larger than its trading partner. The reverse effects are observed when capital is allowed to cross country borders. Using data on unemployment and income distribution for 23 OECD countries, we compute the central parameter in our theoretical model that describes the degree of labour market rigidity. We use this new empirical concept to provide evidence for our theoretical findings by means of reduced‐form regressions as well as simulation results of a calibrated general equilibrium model.     

Allocation of emission permits with leakage through capital markets

This paper analyses how tradable emission permits should be allocated to firms when capital is internationally mobile. When international environmental problems are attempted solved through uncoordinated policies between countries, it might be desirable for the home country to issue free emission permits in proportion to the use of capital in order to prevent leakage through international capital movements. The desirability of free emission permits will however be reduced if capital also can be employed in a domestic non-polluting sector. In this case, it may even be optimal to tax the use of capital in the polluting sector. It is also shown that it is always optimal to subsidise the use of capital in the polluting sector if the use of labour is taxed at an optimal rate. Finally, leakage does not affect the optimal domestic emission limit as long as appropriate capital subsidies and labour taxes are implementeed.