Monopolistically competitive equilibria with differentiated commodities

Summary. An existence theorem of monopolistically competitive equilibrium of the economy in which commodities are subject to differentiation will be proved. We start with the existence theorem of Negishi (1961) and extend it to the commodity space of measures on a compact metric space. In so doing, we have to handle the price normalization carefully. Received: December 2, 1996; revised version: May 6, 1999     

A spatio-temporal model of house prices in the USA

This paper provides an empirical analysis of changes in real house prices in the USA using State level data. It examines the extent to which real house prices at the State level are driven by fundamentals such as real per capita disposable income, as well as by common shocks, and determines the speed of adjustment of real house prices to macroeconomic and local disturbances. We take explicit account of both cross-sectional dependence and heterogeneity. This allows us to find a cointegrating relationship between real house prices and real per capita incomes with coefficients (1,−1)$(1,-1)$, as predicted by the theory. We are also able to identify a significant negative effect for a net borrowing cost variable, and a significant positive effect for the State level population growth on changes in real house prices. Using this model we then examine the role of spatial factors, in particular, the effect of contiguous states by use of a weighting matrix. We are able to identify a significant spatial effect, even after controlling for State specific real incomes, and allowing for a number of unobserved common factors. We do, however, find evidence of departures from long run equilibrium in the housing markets in a number of States notably California, New York, Massachusetts, and to a lesser extent Connecticut, Rhode Island, Oregon and Washington State.     

The long-term impacts of orphanhood on education attainment and land inheritance among adults in rural Kenya

Although the long-term economic impacts of the AIDS epidemic on orphans have been major concerns, few studies have investigated the impacts of orphan status into adulthood. Therefore, this article examines the education attainment and land inheritance of former orphans, who have lost at least one parent before reaching the age of 15 years, by using household surveys in Kenya. We find about a one-year lower educational attainment among former maternal orphans compared with former nonorphans among adults who started schooling before the Free Primary Education program introduced in 1974 but not among adults who started schooling after 1974. On inherited land, we find no significant difference between households headed by former orphans and nonorphans, after controlling for land owned by parents, numbers of brothers and sisters, and birth order among brothers.     

Multidimensional Poverty and Perceived Happiness: Evidence from China,Japan and Korea*

We compare multidimensional poverty and its associations with perceived happiness in China, Japan and Korea. Using largely comparable nationwide survey data, we focus on multidimensional poverty in terms of income, schooling, health and social protection. We find multidimensional poverty to be more prevalent in China than in Japan or Korea; sex and age‐based differences are largest in Korea. We further confirm significant associations between multidimensional poverty and perceived happiness. For all three countries, the aggregated poverty dimensions could largely identify unhappy individuals, with both wider coverage and higher odds than is possible through unidimensional analyses.     

The welfare effect of tariff rate reductions in a many country world

Consider a two-commodity n-country model without inferior goods where import tariffs are the only trade barriers. In this paper we establish that the world's welfare is improved if the country with the highest tariff rate unilaterally reduce its rate to the level of the second highest country or if all the countries of the world reduce tariff rates proportionally. The second rule serves as a theoretical justification of the Kennedy and Tokyo Round Tariff Reductions.     

Intertemporal substitution, risk aversion and ambiguity aversion

Summary. This paper axiomatizes a form of recursive utility on consumption processes that permits a role for ambiguity as well as risk. The model has two prominent special cases: (i) the recursive model of risk preference due to Kreps and Porteus [18]; and (ii) an intertemporal version of multiple-priors utility due to Epstein and Schneider [8]. The generalization presented here permits a three-way separation of intertemporal substitution, risk aversion and ambiguity aversion.Received: 5 August 2003, Revised: 12 March 2004, JEL Classification Numbers: D80, D81, D90.I am grateful to Larry Epstein for his guidance and invaluable advice, and to a referee for helpful comments and suggestions.     

A note on the life-cycle search and matching model with segmented labor markets

Recently, there has been renewed interest in labor search and matching models that incorporate a life-cycle structure by assuming finite horizons. Existing studies provide detailed analyses on the age dynamics of job creation and destruction, assuming that workers of all ages search for jobs in the same market. This paper examines a related environment that has drawn less attention, where the labor market is exogenously segmented by age. The paper finds sufficient conditions for the model to yield unambiguous predictions on the age profiles of key variables, and compares them with the corresponding conditions in models with a single market. The paper further examines the age profiles of these key variables in the efficient allocation. In particular, with no persistence in idiosyncratic match productivity, the efficient allocation is found to exhibit monotonic age profiles for the job finding and separation rates.     

A REFUTATION OF THE COMMODITY EXPLOITATION THEOREM

This note is to show that the generalized commodity exploitation theorem put forward by Bowles and Gintis and Roemer is nothing but an alternative form of the Hawkins–Simon condition for given technical data, and that it has nothing to do with exploitation. That is, the Hawkins–Simon condition means a mere possibility of an economic system to produce a surplus in each commodity, and as such does not guarantee the existence of positive profits. To consider exploitation or the existence of positive profits, we need to introduce prices at which unequal exchanges may be carried out.     

A Generalization of Continuity and Convexity Conditions for Correspondences in Economic Equilibrium Theory

Fixed-point theorems for multi-valued mappings and economic equilibrium existence theorems are generalized from the viewpoint that the continuity and/or convexity assumptions on a mapping may be replaced by weaker local conditions on the vector field defined by the mapping. The generalization gives us natural conditions on individual (possibly non-ordered) preferences or aggregated demand behaviours so that we may obtain several extensions of recent results in social and game-theoretic equilibrium theories.
JEL Classification Numbers: C60, C62, C72, D50, D51.