I welcome any comments, suggestions, and questions that you may have.
To contact me, please send an e-mail to yoshida.hiroyuki 
nihon-u.ac.jp.
I welcome any comments, suggestions, and questions that you may have.
To contact me, please send an e-mail to yoshida.hiroyuki nihon-u.ac.jp.
Dynamics in Linear Cournot Duopolies with Two Time Delays Abstract: Linear differential duopolies are constructed with continuous time scales, constant coefficients and two types of information delays: fixed and continuously distributed time delays. System dynamics are considered with delays in the diagonal terms. By analyzing the associated characteristic equations, it is found that the stability is lost when the lengths of delays cross some critical values. Then it is shown that the destabilizing effect caused by the fixed delays is stronger than the destabilizing effect of the distributed delays having exponentially-declining weighting function. It is further demonstrated that the strength of the destabilizing effect is reversed if the distributed delay has a bell-shaped weighting function. Keywords: |
Economic intermittency in a two-country model of business cycles coupled by investment Abstract: Intermittent behavior of economic dynamics is investigated by a two-country model of Keynes.Goodwin type business cycles. Numerical simulations show that after an economic system evolves from weak chaos to strong chaos the system keeps its memory before the transition and its time series alternates episodically between periods of weakly and strongly chaotic fluctuations. In addition, we examine the intermittent phenomena from the view point of business cycle patterns near the crisis point. Keywords: |
Monetary Contractions and Cumulative Depressions: A Monetary Optimizing Model Abstract: Keywords: |
Harrodian dynamics under imperfect competition: A growth cycle model Abstract: This chapter considers Harrod's knife-edge instability, which implies severe and extreme business cycles restricted by a full employment ceiling and a zero-gross-investment fl oor. We construct a dynamic model with imperfect competition in the output market by using the subjective demand curve approach. In addition, we consider technical choice by taking account of the putty-clay technology. The chapter shows the occurrence of endogenous and moderate fluctuations through the Hopf bifurcation. Keywords: Harrod's knife-edge, Growth cycle, Imperfect competition, Putty-clay technology, Hopf bifurcation |
Monetary Policy and Economic Fluctuations in a Sticky-Price Model Abstract: This paper examines a simple monetary optimizing model with sticky prices. Two types of monetary policy rules are considered: constant money growth rules and interest rate feedback (Taylor-type) rules. In the case of constant money growth rules, we show the existence of limit cycles through the Hopf bifurcation theorem. On the other hand, in the case of the interest-rate feedback rules, we show that active monetary policy leads to the determinacy of equilibrium path, while passive monetary policy induces economic fluctuations. Keywords: Indeterminacy, Hopf bifurcation, Monetary policy |
Dynamic Analysis of Policy Lag in a Keynes-Goodwin Model: Abstract: In this paper, we investigate the impact of government's stabilization policy on the dynamic behavior of the economic system in an analytical framework of a Keynes-Goodwin model of the growth cycle. In particular, we study the effects of the policy lag on macroeconomic stability analytically and numerically. It is shown that the increase of the policy lag contributes to destabilize the system, and cyclical behavior and chaotic motion emerge in some ranges of the parameter values. Keywords: Keynes-Goodwin model, Growth cycle, Policy lag, Hopf bifurcation, Chaotic motion, Numerical simulations |
The possibility of economic slump with the liquidity trap: Abstract: This paper examines the possibility of economic slump with the liquidity trap in a sticky price model. The main findings of the paper are: First, the appearance of recessions and depressions with liquidity traps is observed as equilibrium paths if the government conducts a contractionary monetary policy. Second, the model exhibits the indeterminacy of equilibrium paths. Finally, expansive monetary policy is an effective tool to escape from the liquidity trap, although fiscal stimulus causes full crowding out. |
Coefficient criterion for four-dimensional Hopf bifurcations: Abstract: In this paper, we present a complete mathematical characterization of a coefficient criterion for four-dimensional Hopf bifurcations. Then, we apply our criterion to two typical models of economic dynamics. We consider the two region business cycle model by Puu [Nonlinear economic dynamics, Springer-Verlag, Berlin, 1997] and the dynamic optimization model by Dockner and Feichtinger [J. Econom. 53 (1991) 31]. These applications reveal that our criterion is operative and useful in analyzing the qualitative properties of general four-dimensional dynamic economic models with continuous time. |
Stability, Instability and Complex Behavior in Macrodynamic Models with Policy Lag Abstract: We construct simple macrodynamic models with policy lag by means of mixed difference and differential equations, and study how lags in policy response affect the macroeconomic (in)stability. Local dynamics of the prototype model are studied analytically, and the global dynamics of the prototype and the extended models are studied by means of numerical simulations. We show that the government can stabilize the intrinsically unstable economy if the policy lag is sufficiently short, but the system becomes locally unstable when the policy lag is too long. We also show the existence of cycles and complex behavior in some range of the policy lag. Keywords: Policy lag; Mixed difference and differential equations; Dynamic stability; Hopf bifurcation; Complex behavior |
Nonlinear Dynamics of Policy Lag in Simple Macroeconomic Models Abstract: |
Harrod's ``Knife-edge'' Reconsidered: Abstract: Harrod (1939) concluded that the warranted rate of growth is a unique moving equilibrium, but ``highly unstable'' one. This is named Harrod's knife-edge instability or the Instability Principle. However, his own interpretation of his theory changed over the time. The statements in Harrod (1970, 1973) are good examples: the former admits a multiplicity of dynamic equilibria and the latter introduces an idea which is similar to Leijonhufvud's ``corridor stability.'' The purpose of the present paper is to reconsider his knife-edge instability under the assumptions of putty-clay technology and price-flexibility in the goods market. Our results agree with his later assertions. |
JMacro, Metroeconomica, PuMa, JEBO, Waseda