Optimal production of innovations under uncertainty

The paper reports results on a risk-neutral firm's research incentives. When unrelated to the firm's own stake in the program, the risks encourage or discourage risky research spending, depending on the properties of the research technology available. A non-decreasing time path of information builds the idea of an asymmetric probability distribution of the state of knowledge into the model. It follows that the required return on risky investments may actually fall short of the safe return. Since it is the upside risk that dominates, increased controllable risks will increase incentives for risky innovative activity. It is proved, but only in a more restricted framework (with differentiable processes), that the expectational effects involved will strengthen the positive relationship between controllable risks and the expected return.I am greatly indebted to three anonymous referees for helpful suggestions and to the Yrjö Jahnsson Foundation for financial support.     

On industry equilibrium under uncertainty

The paper considers an industry consisting of numerous firms that produce a homogeneous output, the demand for which is a random variable. Each firm belongs to one of K possible types, and each type is characterized by a U-shaped average cost curve. It is shown that: (i) the first-order necessary conditions for efficient investment and output are sufficient; accordingly, the set of competitive equilibria is non-empty and coincides with the set of efficient allocations; (ii) a dynamic process of free entry and exit of firms, guided by expected profits, is quasistable and every limit point is a competitive equilibrium. The paper also defines a sufficient condition for uniqueness of the competitive equilibrium, in which case it is stable.     

On optimal growth under uncertainty

In a recent paper Brock and Mirman showed that in a one-sector model of economic growth under uncertainty the long-run behavior of the optimal capital stock is governed by the basic properties of an acyclic ergodic Markov process. This paper considers a similar model and has two purposes. First, necessary and sufficient conditions for optimal policy functions are derived in a regime in which future utilities are discounted. These conditions lead, in an example, to an explicit optimal policy function, which is used to display the steady-state solution for the capital stock under an optimal policy. Secondly, in the Brock and Mirman paper it was assumed that the production functions are ordered. We show that all the properties proved by Brock and Mirman are satisfied even when the production functions are not ordered.     

Choice under complete uncertainty: axiomatic characterizations of some decision rules

Summary. We provide characterizations of four new rules for individual decision-making under complete uncertainty. They are what we call the min-max rule, the max-min rule, the lexicographic min-max rule and the lexicographic max-min rule. These rules provide orderings of the sets of possible outcomes associated with uncertain prospects. They provide significant alternatives to commonly-used rules that focus on worst outcomes or best outcomes only, and lexicographic versions of those rules. Received: August 20, 1998; revised version: November 3, 1999     

On the theory of east-west trade under uncertainty

Taking the final stage of the existing socialist economy as the labormanaged economy, this paper establishes a model of East-West trade between a capitalist economy and a labor-managed economy, both of which face asymmetric technological uncertainty. The model reflects the facts that the securities markets for firms' ownership shares exist only in the capitalist economy and that the firm's objective function in the capitalist economy is different from that in the labor-managed economy. It also considers the existence of international forward markets for commodities as international risk-sharing arrangements. Thus, the paper shows that all the basic theorems in traditional trade theory (Factor Price Equalization, Heckscher-Ohlin, Stolper-Samuelson and Rybczynski) carry over to the uncertain environments characterized by different types of economies.This is the final version of the paper, the first draft of which was presented at the 1987 annual meeting of the Japanese Association of International Economics. An earlier version has recently appeared in my book,Competition, Monopoly and International Trade Under Uncertainty (written in Japanese, Tokyo: Asian Economic New Press 1989). I wish to thank professors H. E. Leland, S. Fujino, H. Eguchi, M. Ohyama, K. Otaka, M. Ogawa, T. Ohsawa, K. Fukao, M. Nishijima and two anonymous referees for their helpful comments. Any remaining errors, however, are my responsibility.     

On the investment sensitivity of debt under uncertainty

We investigate the impact of debt on a panel of U.S. manufacturing firms' capital investment behavior as the underlying firm-specific and market-level uncertainty changes. Our estimates show that the influence of leverage on capital investment may be stimulating or mitigating depending on the effects of uncertainty.     

Resource allocation in a general equilibrium model of production under uncertainty

The purpose of this paper is to examine the implications of uncertainty for resource allocation, real income, and income distribution in terms of a simple two-sector general equilibrium model of a small country where uncertainty is introduced by assuming that production in one sector occurs in a stochastic environment. Assuming decreasing risk aversion, we show that an increase in uncertainty causes the movement of the resources away from the uncertain sector, a decline in expected real income, and a shift in the distribution of income against the factor employed intensively by the uncertain sector.     

On the theory of monopolistic competition under demand uncertainty

Establishing a model of a monopolistically competitive industry in which risk-averse Cournot firms act under demand uncertainty and in which the output of individual firms and the number of firms in the industry are both endogenously determined by free entry and exit, this paper attempts to investigate the effects of demand uncertainty on the market equilibrium of a monopolistically competitive industry. It is assumed, for calculus simplification, that the firms are identical in the sense that they have the same monopolistic power and the same production technology. The paper presents some interesting and useful comparative statics results which are contrary to those proposed in the existing papers.This is a revised version of my paper which was firstly presented to the annual meeting of the Japanese Association of International Economics held in 1988 and then included partially in my book published in 1989. I am indebted to professors D. Bös, S. Fujino, M. Ohyama, M. Nishijima, to the members of the Public Economics Research Seminar in Bonn, and to two anonymous referees for their helpful discussions and useful suggestions. Any remaining errors, however, are my responsibility.     

On the theory of the competitive labor-managed firm under price uncertainty

The short-run behavior of a labor-managed firm under competitive assumptions and price uncertainty is analyzed assuming risk aversion. It is compared with its behavior under certainty and the behavior of a capitalist-managed firm under price uncertainty. It is shown that a risk-averse labor-managed firm employs more labor than a risk-neutral labor-managed firm. Generally, uncertainty is seen to have greater impact on the behavior of a labor-managed firm than on the behavior of a capitalist-managed firm. Except under constant risk aversion, the behavior of a labor-managed firm under price uncertainty is less predictable than that of a capitalist-managed firm.     

Lobbying under political uncertainty

This paper considers a model of lobbying described as a common agency game; it departs from the current literature by assuming that the special interest groups are not a priori organized or unorganized and that the type of the politician is not common knowledge. We characterize equilibria when the choice set of the politician consists of two policies; we discuss the conditions leading to efficiency and the characteristics of the groups explaining their relative success in the process of influence. We also offer some results for the general case, including disjoint necessary and sufficient conditions for the equilibria to be efficient.     

Neutral taxation under uncertainty

The analogs under uncertainty of two well-known certainty results are derived: first, if there are timing differences between tax payments and accruals, neutrality is preserved if the resulting tax credits or liabilities are carried forward at the risk-free interest rate, provided that tax credits and liabilities are sure to be redeemed eventually. Second, the invariance of asset valuations with respect to the rate of income tax, at a given pre-tax interest rate, proved by Johansson and Samuelson under certainty, can be extended to cover the case of uncertainty, given analogous ceteris paribus conditions.     

Consumption loans under uncertainty

A stationary equilibrium for a sequence of markets under uncertainty is defined as a stationary stochastic process of temporary market equilibria. The purpose of this paper is to apply this equilibrium concept to a consumption-loans model with stochastic resources. Given that agents live for only two periods, that resources are allocated independently and identically, and that traders make “admissible” consumption decisions, it is shown that the sequence of equilibrium trades on forward markets is a Markov chain. When this chain is strictly stationary with a unique invariant distribution, the sequence of markets is in stationary equilibrium. Using Gale's classification scheme, a strictly stationary chain exists for each type of economy (classical, Samuelson, mixed). Questions concerning convergence to the invariant distribution for each type of economy are addressed by determining when the chain satisfies various recurrence conditions.     

Cobb-Douglas preferences under uncertainty

This paper axiomatizes Cobb-Douglas preferences under uncertainty. First, we extend the original Trockel (Econ Lett 30:7–10, 1989)’s axiomatic foundation to a general state space framework based on the Strong Homotheticity Axiom, obtaining also the incomplete case a la Bewley (Decis Econ Financ 25:79–110, 2002). We show that this key axiom for the Cobb-Douglas expected utility specification is refuted by Ellsberg’s uncertainty aversion behavioral pattern. Our main result provides a set of meaningful axioms characterizing Cobb-Douglas min-expected utility preferences, an important class of uncertainty averse preferences for studying the consequences of ambiguity in finance and other fields. Finally, we present briefly how to obtain more general representations like the variational case.     

Macroprudential policy under uncertainty

Portuguese Economic Journal - In this paper, an index of domestic macroprudential policy tools is constructed and the effectiveness of these tools in controlling credit growth, managing GDP growth...