On Professor Takashi Negishi's contributions to economic theory

Professor Takashi Negishi has made fundamental contributions to economic theory on an extremely broad range of topics. As the editors of this special issue, we feel extremely fortunate that each of us has worked on topics with respect to which Professor Negishi's influences have been particularly large. In this introductory article, each of us will discuss Professor Negishi's influence on the topic we are most familiar with. For the entire spectrum of his research, readers are referred to the list of Professor Negishi's publications presented at the end of this article.     

Effects of international sharing of pollution abatement burdens on income inequality among countries

Improvements in environmental quality will boost output production and hence economic growth. However, although environmental abatement equally benefits all economies in the world, it is shown that, if the private productive resources are not yet accumulated sufficiently in low income economies, income inequality among economies can be widened in the short term not only under equal burden sharing of pollution abatement but even under income-proportional burden sharing. When the marginal productivity is diminishing, the negative effect of the burden is large relative to the positive effect of the improved environment in economies in which resources are not accumulated sufficiently.     

Conjectural Variations and Voluntary Public Good Provision in a Repeated Game Setting

The purpose of this paper is to show how conjectural variations can be derived as a reduced form in an infinitely repeated game of private provision of public goods. We obtain explicit closed forms of conjectural variations associated with maximal sustainable equilibria in which the sum of the utilities of all of a community's members is maximized for both quadratic and Cobb–Douglas preferences, provided that the resulting sequence of contributions can be sustained as a Nash (or subgame perfect) equilibrium in the underlying repeated game. We also show that positive conjectural variations will emerge as long as people place positive weight on the future, and that those conjectures are positively related to the discount factor.     

Trade and Gains from Trade Between Profit-maximizing and Labour-managed Countries with Imperfect Competition

This paper offers a theoretical analysis of trade and the gains from trade in general equilibrium under imperfect competition by assuming that all firms in one country are of the labour-managed type (maximizing the income of labour) while those in the other country are of the profit-maximizing type. Our main conclusion is that if the labour-managed country is larger than or equal to the profit-maximizing country, the profit-maximizing country exports the imperfectly competitive commodity and gains from trade while the labour-managed country exports the perfectly competitive commodity and may lose from trade.     

Trade, Vertical Production Chain, and Competition Policy

The authors build a trade model that renders tractable the process in which imperfect competition in a country's downstream sector affects the rest of the world through international trade. For this purpose, internationally traded goods are viewed as middle products in the vertical chain of production, in which middle products are produced upstream and transformed into final consumption goods downstream. Suppression of competition in a country's downstream sector may serve as a beggar-thy-neighbor policy, increasing that country's own utility while reducing that of its trading partner countries.     

Optimal chaos,nonlinearity and feasibility conditions

Summary This study constructs a class of dynamic models in which optimal paths are generated by nonlinear transition functions similar to a tent map. We provide a sufficient condition under which such a transition function is a chaotic map. This characterization provides a way to construct complex nonlinear dynamics in a broad range of dynamic economic models.We would like to thank Michele Boldrin, William Brock, Richard Day, Mukul Majumdar, Lionel McKenzie, Tapan Mitra, Luigi Montrucchio, Jose Scheinkman, Rangarajan Sundaram and the referees for comments and discussions.     

Ergodic chaos for non‐expansive economic models**

Ergodic chaos is one of the most important concepts in the theory of nonlinear economics. Due to the lack of appropriate sufficient conditions, its reach has not been fully understood. In this paper a sufficient condition for ergodic chaos that covers non‐expansive dynamical systems is examined. By analyzing an endogenous growth model as an example, we discuss the breadth of models in which ergodic chaos can emerge.     

International trade and capital accumulation in an overlapping generations model with a public intermediate good

We investigate the effects of a public intermediate good on trade patterns, capital accumulation, and the gains from trade in a two‐country, three‐sector overlapping generations model. A public intermediate good affects not only the productivity of private production but capital accumulation; thus, the results differ from those obtained in previous studies. First, opening to trade may accelerate capital accumulation in the higher‐savings country. Additionally, the country producing a public intermediate good more (which is labor‐intensive) may be the importer of the investment good (which is the most capital‐intensive). Finally, the lower‐savings country may have lower steady‐state welfare under trade.     

HOME EQUITY IN RETIREMENT

Retired homeowners dissave more slowly than renters, which suggests that homeownership affects retirees' saving decisions. We investigate empirically and theoretically the life-cycle patterns of homeownership, housing, and nonhousing assets in retirement. Using an estimated structural model of saving and housing decisions, we find first that homeowners dissave slowly because they prefer to stay in their house as long as possible but cannot easily borrow against it. Second, the 1996–2006 housing boom significantly increased homeowners' assets. These channels are quantitatively significant; without considering homeownership, retirees' net worth would be 28%–44% lower, depending on age.