Capital Accumulation and Resource Depletion: A Hartwick Rule Counterfactual

How much produced capital would resource-abundant countries have today if they had actually followed the Hartwick Rule (invest resource rents in other assets) over the last 30 years? We employ time series data on investment and rents on exhaustible resource extraction for 70 countries to answer this question. The results are striking: Venezuela, Trinidad and Tobago, and Gabon would all have as much produced capital as South Korea, while Nigeria would have five times its current level. A specific rule for sustainability – maintain positive constant genuine investment – is shown to lead to unbounded consumption. Copyright Springer 2006Hartwick rule, exhaustible resources, sustainable development, Q01, Q32, Q56,

Determinants of urban sprawl in European cities

This paper provides empirical evidence that helps to answer several key questions relating to the extent and causes of urban sprawl in Europe. Building on the monocentric city model, this study uses existing data sources to derive a set of panel data for 282 European cities at three time points (1990, 2000 and 2006). Two indices of urban sprawl are calculated and respectively reflect changes in artificial area and the levels of urban fragementation for each city. These are supplemented by a set of data on various economic and geographical variables that might explain the variation of these indices. Estimating using a Hausman Taylor and random regressors to control the possible correlation between explanatory variables and unobservable city-level effects, we find that the fundamental conclusions of the standard monocentric model are valid in the European context for both indices. Although the variables generated by the monocentric model explain a large part of variation of artificial area, their explanatory power for the fragmentation is relatively low.Ce papier étudie les causes de l'étalement urbain dans le contexte européen. Sur la base d'un modèle de ville monocentrique, nous exploitons plusieurs sources de données portant sur 282 aires urbaines et trois périodes de références 1990, 2000 et 2006. Deux indicateurs de l'étalement ont été utilisés : la superficie artificialisée et fragmentation urbaine. Ces deux indicateurs ont été confrontés à un ensemble de variables économiques et géographiques. Afin de contrôler les corrélations possibles entre les variables explicatives et l'hétérogénéité des observations individuelles, nous avons utilisé à la fois une régression à la Hausman Taylor et une régression aléatoire. Bien que les principales conclusions du modèle monocentrique aient été confirmées, son pouvoir explicatif de la fragmentation est relativement faible