The likelihood of dubious election outcomes

Summary. A disturbing phenomenon in voting, which causes most of the problems as well as the interest in the field, is that election outcomes (for fixed preferences) can change with the way the ballots are tallied. This causes difficulties because with each possible choice, some set of voters can be dubious about whether it is the “correct” one. But, how likely are these settings allowing multiple election outcomes? By combining properties of the geometry of voting developed by Saari with a analytic-geometric technique created by Schlafli, we determine the likelihood that a three candidate election can cause these potentially dubious outcomes. Received: April 11, 1997; revised version: November 12, 1997     

On Lipschitz continuity of policy functions in continuous-time optimal growth models

Summary. This paper proves the C ^1,1 differentiability of the value function for continuous time concave dynamic optimization problems, under the assumption that the instantaneous utility is C ^1,1 and the initial segment of optimal solutions is interior. From this result, the Lipschitz dependence of optimal solutions on initial data and the Lipschitz continuity of the policy function are derived, by adding an assumption of strong concavity of the integrand. Received: July 29, 1996; revised version: November 25, 1997     

Stochastic convexity in dynamic programming

Summary. This paper explores sufficient conditions for a continuous stationary Markov optimal policy and a concave value function in stochastic dynamic programming problems. Also, the paper addresses conditions needed for the differentiability of the value function. The paper uses conditions such as first order stochastic dominance, second order stochastic dominance and concave stochastic dominance that are widely applied in economics. Received: February 23, 2001; revised version: May 19, 2002 RID="*" ID="*" I am deeply indebted to Prajit Dutta for patient assistance and advice. This paper has benefited from discussions with Tsz Cheong Lai, Tackseung Jun, Werner Stanzl and Satyajit Bose as well as feedback from an anonymous referee.     

Monte Carlo simulation of macroeconomic risk with a continuum of agents: the symmetric case

Summary. Suppose a large economy with individual risk is modeled by a continuum of pairwise exchangeable random variables (i.i.d., in particular). Then the relevant stochastic process is jointly measurable only in degenerate cases. Yet in Monte Carlo simulation, the average of a large finite draw of the random variables converges almost surely. Several necessary and sufficient conditions for such “Monte Carlo convergence” are given. Also, conditioned on the associated Monte Carlo -algebra, which represents macroeconomic risk, individual agents' random shocks are independent. Furthermore, a converse to one version of the classical law of large numbers is proved. Received: October 29, 2001; revised version: April 24, 2002 RID="*" ID="*" Part of this work was done when Yeneng Sun was visiting SITE at Stanford University in July 2001. An early version of some results was included in a presentation to Tom Sargent's macro workshop at Stanford. We are grateful to him and Felix Kübler in particular for their comments. And also to Marcos Lisboa for several discussions with Peter Hammond, during which the basic idea of the paper began to take shape. Correspondence to: P.J. Hammond     

Bank structure, capital accumulation and growth: a simple macroeconomic model

Summary. This paper analyzes the equilibrium growth paths of two economies that are identical in all respects, except for the organization of their financial systems: in particular, one has a competitive banking system and the other has a monopolistic banking system. In addition, the sources of inefficiencies, as a result of monopoly banking, and their relationship to the existence of credit rationing are explored. Monopoly in banking tends to depress the equilibrium law of motion for the capital stock for either of two reasons. When credit rationing exists, monopoly banks ration credit more heavily than competitive banks. When credit is not rationed, the existence of monopoly banking leads to excessive monitoring of credit financed investment. Both of these have adverse consequences for capital accumulation. In addition, monopoly banking is more likely to lead to credit rationing than is competitive banking. Finally, the scope for development trap phenomena to arise is considered under both a competitive and a monopolistic banking system. Received: September 20, 1999; revised version: December 3, 1999     

Elasticity of substitution and growth: normalized CES in the Diamond model

Summary. It is often asserted that the more substitutable capital and labor are in the aggregate production the more rapidly an economy grows. Recently this has been formally confirmed within the Solow model by Klump and de La Grandville (2000). This paper demonstrates that there exists no such monotonic relationship between factor substitutability and growth in the Diamond overlapping-generations model. In particular, we prove that, if capital and labor are relatively substitutable, a country with a greater elasticity of substitution exhibits lower per capita output growth in transit and in steady state. Received: October 27, 2001; revised version: February 25, 2002     

Approximation by finite horizons of the undiscounted one-sector growth model

Summary. In this paper I give a method for finding long-run-average policies in the undiscounted economic growth problem using approximations by finite horizons. Required hypothesis is the strong interiority of T-horizon solutions. Received: March 25, 1996; revised version: July 29, 1997     

A dynamic analysis of an endogenous growth model with leisure

Summary. The main goal in this paper is to analyze an economic model of endogenous growth where human capital accumulation acts as the engine propelling economic activity. The added ingredient in our model is that agents derive utility from consumption and leisure, where leisure is defined as the amount of time devoted to those activities augmented by the level of education. Under regular conditions we show that there is a unique globally stable balanced growth path. We also provide a characterization of the behavior of our economic variables along the transition. Received: May 26, 1998; revised version: September 9, 1999     

A new proof of the maximum principle

Summary. We offer a new proof of the maximum principle, by using the envelope theorem that is frequently used in the standard microeconomic theory. Received: April 11, 2002; revised version: June 26, 2002 Correspondence to: K. Shimomura     

Government financing in an endogenous growth model with financial market restrictions

Summary. In this paper, we develop an endogenous growth model with market regulations on explicitly modeled financial intermediaries to examine the effects of alternative government financing schemes on growth, inflation, and welfare. In the presence of binding regulation, there is always a unique equilibrium. We perform four alternative policy experiments; a change in the seigniorage tax rate, a change in the seigniorage tax base, a change in the income tax and a change in the fiscal-monetary policy mix. We find that in the presence of binding legal reserve requirements, a marginal increase in government spending need not result in a reduction in the rate of economic growth if it is financed with an increase in the seigniorage tax rate. Raising the seigniorage tax base by means of an increase in the reserve requirement retards growth and it has an ambiguous effect on inflation. An increase in income tax financed government spending also suppresses growth and raises inflation although not to the extent that the required seigniorage tax rate alternative would. Switching from seigniorage to income taxation as a source of government finance is growth reducing but deflationary. From a welfare perspective, the least distortionary way of financing an increase in the government spending requirements is by means of a marginal increase in the seigniorage tax rate. Under the specification of logarithmic preferences, the optimal tax structure is indeterminate. Received: March 20, 2000; revised version: June 26, 2001     

Stochastic growth with a likelihood-increasing estimation process

Summary. We formulate an optimal estimation process in a stochastic growth model with an unknown true probability model. We consider a general reduced model of capital accumulation with an infinite horizon and introduce a learning process in the stochastic dynamic programming. When the only available information is a sample realization generated by a stationary and ergodic stochastic process, we prove that the optimal estimation process based on likelihood-increasing behavior converges to the true probability measure and the likelihood-increasing estimator defines a transition function on the sample space.Received: 24 January 2004, Revised: 18 February 2005, JEL Classification Numbers: C13, C44, C61, O41.An earlier version of this paper was presented at the annual Meeting of the Japanese Economic Association at the University of Tokyo, at the annual Conference of the Japan Society for Industrial and Applied Mathematics at Keio University, and at the 7th Czech-Japan Seminar on Data Analysis and Decision Making under Uncertainty in Awaji Island. I have benefited from useful comments from Hidetoshi Komiya, Andrew McLennan, Toru Maruyama, Nancy Stokey, Shinichi Suda, Shin-Ichi Takekuma, Akira Yamazaki, and an anonymous referee. I would also like to thank Fumihiro Kaneko for invaluable technical discussions. This research was partly supported by Grant-in-Aid for Scientific Research (No. 14730021) from the Japan Society for the Promotion of Science.     

Business cycles in a two-sector model of endogenous growth

Summary. This paper analyzes the impact of cyclical volatility on long-term economic growth: does growth increase or decrease with increased cyclical volatility? We construct a stochastic two-sector model of endogenous growth to analyze this question in detail. We will show that economic growth is higher in the presence of business cycles, since people devote more time to learning activities in an uncertain economic environment. Human capital is a hedge against future income uncertainty. Hence, the rate of economic growth will be higher in a stochastic environment. Based on a calibration of the model, we find that economic growth increases by 0.46%-point as a result of observed business cycle variability. When account is taken of the interaction between the model's general equilibrium and the cycle, welfare gains (measured in units of a permanent percentage increase in consumption) from eliminating business cycle volatility are approximately 1.87%. Received: January 25, 2000; revised version: November 3, 2000     

Global asymptotic stability of a competitive equilibrium with recursive preferences

Summary. This paper demonstrates global stability of a competitive equilibrium in a multi-sector model of many firms, each of which exhibits constant returns to scale technology, and of infinitely lived consumers, whose preferences are recursive but not necessarily additively separable. In the topology induced by a sup-norm, the dominant diagonal blocks condition (Araujo and Scheinkman (Econometrica 45, 1977)) allows us to apply the implicit function theorem to obtain continuity of the equilibrium path. If a stationary equilibrium is locally asymptotically stable, then the continuity of the equilibrium path and smoothness of a weight function on heterogeneous consumers imply that all equilibrium paths converge to the steady state. The dominant diagonal blocks condition is also shown to be sufficient for the local asymptotic turnpike property. Received: December 13, 1996; revised version: June 2, 1999     

A turnpike property of optimal programs for a class of simple linear models of production

Summary. This paper establishes a ‘turnpike theorem’ for a closed linear model of production with a primitive input requirement matrix. Optimal programs of resource allocation have a ‘turnpike property’ if the growth factor of every sector in the economy converges, in the long run, to a common value. The usefulness of such a theorem is due to the fact that the input requirement matrix for an economy with a large number of goods may be primitive (some power of the matrix is strictly positive). Received: April 19, 1998; revised version: July 15, 1998     

Weak measurability and characterizations of risk

Summary. In the context of a continuum of random variables, arising, for example, as rates of return in financial markets with a continuum of assets, or as individual responses in games with a continuum of players, an important economic issue is to show how idiosyncratic risk can be removed through some device of aggregation or diversification when such risk is explicitly introduced into the model. In this paper, we use recent work of Al-Najjar [1] as a general backdrop to provide a review of the basic issues involved when the continuum is formulated as the Lebesgue interval. We present two examples to argue that the fundamental problem of the non-measurability of sample functions, originally identified by Doob, and further elaborated by Feldman, Gilles and Judd in the economic literature, simply cannot be bypassed by reinterpretations of standard results. We also provide an equivalence result in the spirit of Al-Najjar's efforts; but argue that this elementary result does not go beyond the standard law of large numbers for a sequence of real-valued iid random variables, and as such, is incapable of yielding anything of substantive economic interest beyond this law. Received: April 23, 1998; revised version: April 28, 1998     

Externalities, expectations, and growth

Summary. The paper studies a model of accumulation and growth where a continuum of heterogeneous firms play dynamically optimal strategies along a (rational expectations) equilibrium. The key feature of the model is that firms' technological decisions are assumed subject to both friction and external effects. This gives rise to a wide multiplicity of equilibrium behavior, any path of sustained growth requiring that the economy tackle a never-ending chain of fresh coordination problems. This setup is modelled as a (non-atomic) dynamic game, suitable conditions being provided that partially characterize when sustained growth is a possible (never the unique) equilibrium outcome. Received: May 25, 1995; revised version: March 25, 1998     

Preference profiles sustaining Arrow's theorem

Summary. Arrow's theorem is proved on a domain consisting of two types of preference profiles. Those in the first type are “almost unanimous": for every profile some alternative x is such that the preferences of any two individuals merely differ in the ranking of x, which is in one of the first three positions. Profiles of the second type are “appropriately heterogeneous”, with preferences similar to those generating the “paradox of voting”. Received: March 9, 2000; revised version: June 7, 2001     

Can market power sustain endogenous growth in overlapping-generations economies?

Summary. Sustained endogenous growth is known to be impossible in OLG one-sector models without non-convexities and externalities, unless income is redistributed to the young generation. No redistribution proper is however necessary, as shown in two simple examples, if positive profits accruing to young monopolistic entrepreneurs can be sustained in equilibrium, and/or if young unionised workers can guarantee a non-vanishing share of aggregate income. In this context, market power appears, in two different forms, as a significant source of sustained endogenous growth. Received: October 3, 2000; revised version: March 9, 2001     

Stochastic strategy adjustment in coordination games

Summary. The paper explores a model of equilibrium selection in coordination games, where agents from an infinite population stochastically adjust their strategies to changes in their local environment. Instead of playing perturbed best-response, it is assumed that agents follow a rule of ‘switching to better strategies with higher probability’. This behavioral rule is related to bounded-rationality models of Rosenthal (1989) and Schlag (1998). Moreover, agents stay with their strategy in case they successfully coordinate with their local neighbors. Our main results show that both strict Nash equilibria of the coordination game correspond to invariant distributions of the process, hence evolution of play is not ergodic but instead depends on initial conditions. However, coordination on the risk-dominant equilibrium occurs with probability one whenever the initial fraction contains infinitely many agents, independent of the spatial distribution of these agents. Received: March 14, 2000; revised version: June 21, 2001     

On Intersectoral allocations,factors substitutability and multiple long-run growth paths

Summary. This article considers a two-sector model of economic growth with “labour-augmenting” intersectoral external effects stemming from the aggregate capital stock. It is shown that equilibrium balanced growth paths with a non-trivial labour allocation scheme become available. A set of sufficient conditions for the existence of multiple equilibrium growth rays is provided and their determinacy properties are then characterised. Finally, examination of a parameterised C.E.S. economy illustrates the central role of non-unitary values for the elasticity of substitution in the multiplicity issue. Received: October 31, 2000; revised version: September 25, 2001