Stochastic growth: a duality approach

We re-examine the representative agent's optimal consumption and savings under uncertainty in the presence of investment constraints using martingale representation and convex analysis techniques. This framework allows us to explicitly quantify precautionary savings which induces a higher average growth rate than in a certainty setup. We provide a closed form solution for a Cobb-Douglas economy. The effect of uncertainty on portfolio selection is analyzed. Consumption growth rate and risk free interest rate exhibit a U-shaped relationship. Uncertainty negatively affects expected consumption growth rate; such a result seems to be supported by empirical evidence.     

Excess demand functions with incomplete markets—a global result

The purpose of this paper is to give a global characterization of excess demand functions in a two-period exchange economy with incomplete real asset markets. We show that continuity, homogeneity and Walras’ law characterize the aggregate excess demand functions on any compact price set which maintains the dimension of the budget set.     

Market microstructure in a global B2B network

On‐line marketplaces raise several interesting issues, among them the relevance of location when content is digitized, and the assessment of a supplier's capabilities when buyers worldwide only have electronic contact with sellers. In global B2B on‐line marketplaces, market microstructures, i.e. which firms compete for the same customers, are thus likely to be influenced by how customers value location and firm capabilities in their decisions to do business with different suppliers on‐line. We suggest that both these sets of attributes will continue to matter on‐line—firms possessing similar capabilities, as well as firms that are similar in location by country, time zones or clusters, will compete for business from the same customers. We model the similarity in competitive positions between pairs of firms based on the overlap in their customer networks, using data on actual interactions between supplier and customer banks on an electronic trading system. Using QAP network regression techniques on the 100 largest banks in this industry, we find that similarity in capabilities influences who competes with whom, and that location still matters in a global B2B exchange. Interestingly, location influences who a firm's competitors are, but not where its customers are from. Copyright © 2001 John Wiley & Sons, Ltd.     

Competitive equilibria with limited enforcement

We show how to decentralize constrained efficient allocations that arise from enforcement constraints between sovereign nations. In a pure exchange economy these allocations can be decentralized with private agents acting competitively and taking as given government default decisions on foreign debt. In an economy with capital these allocations can be decentralized if the government can tax capital income as well as default on foreign debt. The tax on capital income is needed to make private agents internalize a subtle externality. The decisions of the government can arise as an equilibrium of a dynamic game between governments.     

Economic Implications of Alternative Allocation Schemes for Emission Allowances*

For reasons of political feasibility, emission trading systems may have to rely on free initial allocation of emission allowances in order to ameliorate adverse production and employment effects in dirty industries. Against the background of an emerging European‐wide emission trading system, we examine the trade‐off between such compensation and economic efficiency under output‐based and emissions‐based allocation rules. We show that the emissions‐based allocation rule is more costly than the output‐based rule in terms of maintaining output and employment in energy‐intensive industries. When the international allowance price increases, the inferiority of emissions‐based allocation vis‐à‐vis output‐based allocation becomes more pronounced, as emission subsidies drastically restrict efficiency gains from international trade in emission allowances.     

Cities under stress

This paper studies the effect of terrorist attacks on the internal structure of cities. We develop an urban framework with capital structures suitable for the study of this question and analyze the long and short term implications of this type of events. In the long run, the analysis shows that a terrorist attack will affect urban structure only modestly, relative to the potentially large decrease in the level of economic activity in the city. Land rents will not decline at all locations. In the short run, agglomeration forces will amplify the effect of the original destruction and will reduce urban economic activity temporarily.     

Entry and growth in a perfectly competitive vintage model

A perfectly competitive vintage-knowledge model of Schumpeterian growth is introduced to study the relation between growth, technology-lifetime, entry, and productivity-dispersion. The incentive to innovate is generated by the productivity-dispersion (latent in traditional vintage models) between new and old plants, rather than by monopoly rents. The model has a unique steady-state REE with endogenous growth. The endogenous extent of entry constitutes a buffer, dampening the effect of research-efficiency and completely neutralizing the effect of population size or population growth rates on per-capita income levels and growth rates. Variations of research-efficiency lead to a negative relation between growth and vintage-lifetime and a non-monotonic relation between growth and productivity-dispersion.     

METROPOLITAN HOUSE PRICES IN SOUTH AFRICA: DO THEY CONVERGE?

The question this paper investigates is whether or not different metropolitan areas each constitute a separate housing market or whether or not there is a single South African housing market. Theory on the Law of One Price suggests that if products or geographic areas belong in the same market, their absolute prices must converge, so that their relative prices are stationary. By using cross-sectional time series data of five metropolitan areas, the paper tests for the Law of One Price by applying the Im, Pesaran and Shin panel unit root test. The paper finds strong evidence of convergence in large middle-segment house prices and weaker support for convergence in medium middle-segment house prices. In addition, the paper finds no evidence for convergence in small middle-segment house prices. This suggests the existence of a national market for large and possibly middle-segment houses in metropolitan areas, but separate metropolitan markets for small middle-segment houses. In addition, the paper estimates the speed of convergence and finds that large middle-segment house prices converge within two to seven quarters, while the speed of convergence for medium middle-segment house prices in three of the five areas is five to eight quarters.     

Hedging,Financing and Investment Decisions: A Simultaneous Equations Framework

We empirically investigate the interactions among hedging, financing, and investment decisions. We argue that the way in which hedging affects a firm's financing and investing decisions differs for firms with different growth opportunities. We find that high growth firms increase their investment, but not leverage, by hedging. However, we also find that firms with few investment opportunities use derivatives to increase their leverage.     

Technical Efficiency Estimates of Scottish Agriculture: A Note

Within the UK there has been a lack of studies of technical efficiency at the Scottish level. This note compares the results obtained using Scottish data with a recent study by Hadley [Journal of Agricultural Economics (2006) Vol. 57, pp. 81–100] for English and Welsh farms. Four major sectors are investigated, namely: (i) cereals, (ii) dairy, (iii) sheep and (iv) beef over the period 1989 to 2004. Some distinct differences in efficiencies, returns to scale and causes of efficiency are found.