Aggregation effects on price and expenditure elasticities in a quadratic almost ideal demand system

Abstract.  While it is well known that demand elasticities calculated at the macro level will in general differ from those calculated at the micro level because of aggregation effects, there remain the questions of how large the effects are and how they vary with the degree of inequality in the income distribution. We explore these questions with models based on a quadratic version of the Almost Ideal Demand System. We investigate the elasticity differences theoretically and then calibrate the models and generate numerical results, using income data for seven countries with widely different distributions. The aggregation effects are found generally to be rather small, even with highly unequal income distributions.     

Entry deterrence through credit denial

Firms in oligopoly can use debt to commit to a strategic position that negatively affects rival firms and improves profitability. In this paper, I show that an incumbent firm can deter entry by using debt to commit to such a low price that an entrant's lender will not finance entry, even if the entrant's expected profit from entry is positive. Empirical evidence shows that concentration and debt are positively related in several industries, indicating that debt may be used to reduce competition.     

The Determinants of Tying Litigation, 1961–2001

The idea that changes in Supreme Court decision rules should have measurable effects on the volume of cases litigated has a compelling plausibility, and several models of litigation predict this result. The prediction is a fragile one, however, because it implies very restrictive assumptions about the probability distributions of the cases subject to dispute. The period studied includes four Supreme Court decisions widely regarded as changing the rules and altering the level of uncertainty surrounding the legality of the anti-tying provisions of the antitrust laws. Broad trends in antitrust activity generally and changes in firm profitability statistically explain over three-quarters of the observed variation in tying litigation. Changes in legal precedent have only modest effects upon litigation.

Child malnutrition and school performance in China

Data on the height, weight, age and grade level of over 3,000 children in five quite different locations in China allow computation of how far behind in school each child is, relative to where he should be given his age, as well as of the nutritional status variables of height-for-age, weight-for-age and weight-for-height. This paper uses these data to estimate the impact of the nutritional variables on the available measure of school performance. Children tend to be about one grade further behind in rural areas than in the provincial capitals, and about one-half a grade further behind in the provincial capitals than in Beijing. Even after controlling for location, however, lower nutritional status (particularly height-for-age) was found to affect school performance adversely; a one standard deviation reduction in height-for-age, for example, would result in a child's being about one-third of a year further behind. Though results from a geographically limited sample should be generalized only with substantial caution, and alternative interpretations of the data are possible, it does appear likely that malnutrition in rural China remained sufficiently prevalent in 1979 to retard the school advancement of large numbers of children.     

Does trade liberalization harm the environment? A new test

Some believe that relatively lenient environmental standards give developing countries a comparative advantage in pollution–intensive goods. Thus, freer trade will harm their environment. This paper brings together the literature on openness and growth, and on the environmental Kuznet’s curve, to demonstrate that the opposite may be true. A simultaneous–equations system is derived which incorporates multiple effects of trade liberalization on the environment. Estimation using pooled provincial data on Chinese water pollution, suggests that freer trade aggravates environmental damage via the terms of trade, but mitigates it via income growth. Simulations suggest that the net effect in China was beneficial. JEL Classification: Fl3, Q28, 0l9 Est–ce que la libéralisation du commerce est nuisible pour l’environnement? Un nouveau test. Certains croient que des normes environnementales relativement peu contraignantes donnent un avantage comparatif aux pays en voie de développement dans la production de biens qui polluent intensivement. Donc, un commerce plus libre contribuera à nuire à l’environnement. Ce mémoire synthétise la littérature spécialisée sur l’ouverture des marchés et la croissance, ainsi que sur la courbe de Kuznets, pour montrer que l’inverse est vrai. On dérive un système d’équations simultanées qui incorpore les multiples effets de la libéralisation du commerce sur l’environnement. La calibration de ce système, en utilisant de manière intégrée les données provinciales de pollution de l’eau en Chine, suggère qu’un commerce plus libre aggrave l’état de l’environnement par le truchement du jeu des termes d’échange, mais que cet effet est mitigé par l’effet de croissance des revenus. Des simulations suggèrent que l’effet net en Chine est positif.     

A dynamic perspective on the impact of process innovation upon competitive strategies

The paper lays the foundation for building a dynamic theory of the impact of process innovation upon competitive strategies. An innovation is tracked over two and a half decades to observe changing patterns in competition resulting from ongoing innovation development, emerging complementary technologies, and expanding use. The study finds that the innovation created competitive opportunities and threats for both firms that adopted it and those that did not.