Ngo Van Long and Koji Shimomura
"Some results on the Markov equilibria of a class of homogeneous differential games"
Journal of Economic Behavior and Organization
We consider the class of differential games with transition dynamics and constraints
that are homogeneous of degree one. We show that if the integrand of the objective function
is homogeneous of degree a, then best replies to linear homogeneous Markov strategies
are linear homogeneous, and the value function is homogeneous of degree a. A paralell result
holds when one applies logarithmic transformation to the integrand. Examples are provided.
Koji Shimomura (Kobe University)
"A dynamic equilibrium model of durable-goods monopoly"
Journal of Economic Behavior and Organization
In this paper we consider a simple dynamic equilibrium model of durable-goods monopoly
in a discrete time framework and show that a revised Coase Conjecture, "Monopolists are
efficient under a proper tax-subsidy policy", holds even in the case of increasing marginal cost
if the length of each period in the discrete model is sufficiently short.
Been-Lon Chen and Koji Shimomura
"Self-Fulfilling Expectations and Economic Growth:
A Model of Technology Adoption and Industrialization"
International Economic Review ( February 1998 )
In this work, we constructed a model that integrates both industrialization and
endogenous growth. We feature the role of technology adoption in sustaining growth
and achieving industrialization. Our economy contains multiple equilibria for an initial
history. We found that only self-fulfilling expectations matter in selecting an equilibrium,
whereas history plays no role. Our equilibrium is shown to involve a threshold property:
when the economy starts above this threshold, the economy is able to sustain growth:
otherwise, it is not. Both the rate of economic growth and the process of industrialization
increase gradually and approach an upper bound.
M. C. Kemp and Koji Shimomura
"Increasing Returns and International Trade"
Review of International Economics
We develop a model of international trade with increasing returns to scale by taking
into account the possibility of cooperation among agents in an egalitarian economy.
It is shown that each country gains from trade in a trading world in which there are
arbitrary numbers of increasing-returns-to-scale goods, constant-returns-to-scale goods,
factors of production and countries.
Fumio Dei (Kobe University)
Japanese Economic Review
The degree of industrialization in a country can be measured by the diversity of
intermediate goods produced in the country. I construct a small-country model
in which this diversity is determined endogenously in the process of industrialization.
My model shows that the characteristics of equilibria depend on the substitutability
among intermediate goods; particularly when the substitutability is large, there may
be multiple equilibria. When such equilibria exist, optimistic expectations lead to
a high degree of industrialization but pessimistic expectations yield a low degree
of industrialization.
Makoto Yano (Keio University)
This study establishes two main results in a dynamic general equilibrium model.
The first is to demonstrate the dual Liapounov stability of a von Neumann facet
without the restrictive assumptions on the structure of underlying technologies
that are commonly adopted in the optimal growth literature. The second result is
to demonstrate that a temporary change in fiscal policy has almost no effect on
present and future consumption. While such inefficacy of temporary fiscal policy
has been discussed in the context of permanent income hypothesis, in this study,
it is proved in the dynamic general equilibrium framework under a set of basic
assumptions of general equilibrium theory.
M. C. Kemp and Koji Shimomura
"Trade Gains: A Unified Exposition Based on Duality"
Japanese Economic Review
This paper presents the well established gains-from-trade propositions of
perfect competition in a unified form based on fundamental duality concepts.
M. C. Kemp, M. Okawa and Koji Shimomura
"Voluntary Export Restraints and Economic Welfare:
A General Equilibrium analysis"
Japanese Economic Review
We derive some sufficient conditions for the Suzumura-Ishikawa proposition
on voluntary export restraints to hold when their model is extended to
a general equilibrium framework. The sufficient conditions are concerned
with the magnitude of income effects which plays no role in the
partial-equilibrium analysis of Suzumura and Ishikawa.
Koji Shimomura (Kobe University)
"A Geometric Approach to the Stolper-Samuelson Theorem"
International Economic Review ( August 1997 issue)
This paper presents a pair of new equivalent conditions for a given
n x n matrix of distributive shares to satisfy the Stolper-Samuelson
criterion. Specifying n as 4 and making use of barycentric coordinates,
we give geometric characterization to the equivalent onditions.
Shinsuke Ikeda (Osaka University) and Yoshiyasu Ono (Osaka University)
"Fiscal Policy, Wealth Divergence, and Lifetime Utility"
Journal of Economics (Zeitschrift fur Nationalokonomie)
Using a two-country dynamic optimization model where the less patient
country decumulates and the more patient one accumulates wealth,
we analyze spill-over effects of lump-sum and consumption taxes.
A lump-sum tax on a country definitely harms the other country
through a change in the rate of interest. A lump-sum tax on either country
always improves the less patient country's asset position. A consumption
tax has no spill-over effect, although it is Pareto-inferior. Applying these
results into a closed-country context with heterogeneous agents, we also
discuss policy implications of a discriminatory tax.