Consistent estimation of discrete-choice models for panel data with multiplicative effects

This paper presents an extension to the fixed-effect Logit for panel-data discrete-choice models, where the error component structure is multiplicative (individual effects multiplied by time effects). In linear models with such an error-component structure as investigated by Ahn, Lee and Schmidt (2001), usual fixed-effect estimators are generally inconsistent. We propose a conditional Logit estimator based on a different sufficient statistic, for the case where multiplicative time effects are known. When not the case, we discuss the implementation of the Modified Profile Likelihood based on a transformation of incidental parameters. The last estimator is an extension of Honoré and Lewbel (2000) semiparametric estimator. We investigate small sample properties of these estimators with a Monte Carlo experiment.

Land Use, Production Growth, and the Institutional Environment of Smallholders: Evidence from Burkinabe Cotton Farmers

The cotton boom in Burkina Faso consisted of a growth in cotton land shares together with an overall increase in total cultivated land. This paper examines the impact of institutional changes in the cotton sector on the evolution of smallholders’ land-use decisions. The empirical analysis is supported by a structural model that takes into account the specific institutional features of the Burkinabè cotton sector and builds upon household level data collected in rural Burkina Faso. We attribute most of the change in land use to the newly established institutional arrangements between producers and stakeholders, mechanization, and slackening of the food security constraint.Burkina Faso, Cotton, Land Use, Commodity Reform, Institutional Arrangements, Farm Management, Financial Economics, N57, 013, O33, Q15, Q18,

A Note on Indeterminacy in Overlapping Generations Economies with Environment and Endogenous Labor Supply

We consider an overlapping generations model with environment and an elastic labor supply. In this framework, consumers have to choose between consumption, environmental quality, and leisure. We show the existence of both deterministic cycles and indeterminacy. In contrast to previous results, the emergence of endogenous fluctuations does not require a high emission rate of pollution.Environment ; labor supply ; overlapping generations ; indeterminacy ; endogenous cycles

Environment in an Overlapping Generations Economy with Endogenous Labor Supply : a Dynamic Analysis.

We consider an overlapping generations model with environment, where we introduce an elastic labor supply. In this framework, consumers have to choose between consumption, environmental quality and leisure. We establish that several steady states can coexist, even under a Cobb-Douglas technology, and we put in evidence a non monotonic relationship between pollution and per capita income, as suggested by the Environmental Kuznets Curve. Moreover studying local dynamics, we show the existence of deterministic cycles and endogenous fluctuations due to self-fulfilling expectations. In contrast to previous results, the occurrence of such fluctuations does not require a high emission rate of pollution. Finally, we discuss some welfare and policy implications of our results. Especially, we show that a government which would reduce pollution emissions can face a trade-off between an increase of steady state welfare and an intergenerational welfare inequality due to indeterminacy.Environment, Labor supply, Overlapping generations, Multiplicity of steady states, Environmental Kuznets Curve, Indeterminacy, Endogenous cycles.

Pollution as a source of endogenous fluctuations and periodic welfare inequality in OLG economies.

This article examines the conditions under which endogenous fluctuations and periodic welfare inequality can emerge in OLG economies having an environmental dimension.Endogenous fluctuations; Environmental quality; Intergenerational equity

Mean flow anisotropy without waves in rotating turbulence

We tackle the question of how anisotropy in flows subject to background rotation favours structures elongated along the rotation axis, especially in turbulent flows. A new, wave-free mechanism is identified that challenges the current understanding of the process. Inertial waves propagating near the rotation axis are generally accepted as the most efficient mechanism to transport energy anisotropically. They have been shown to transfer energy to large anisotropic, columnar structures. Nevertheless, they cannot account for the formation of simpler steady anisotropic phenomena such as Taylor columns. Here, we experimentally show that more than one mechanism involving the Coriolis force may promote anisotropy. In particular, in the limit of fast rotation, that is at low Rossby number, anisotropy favouring the direction of rotation of the average of a turbulent flow arises neither because of inertial waves nor following the same mechanism as in steady Taylor columns, but from an interplay between the Coriolis force and average advection.Comment: 17 pages, 10 figures, submitted to Jour. Fluid Mec

Transition between advection and inertial wave propagation in rotating turbulence

In turbulent flows subject to strong background rotation, the advective mechanisms of turbulence are superseded by the propagation of inertial waves, as the effects of rotation become dominant. While this mechanism has been identified experimentally (Dickinson & Long, J. Fluid Mech., vol. 126, 1983, pp. 315–333; Davidson, Staplehurst & Dalziel, J. Fluid Mech., vol. 557, 2006, pp. 135–144; Staplehurst, Davidson & Dalziel, J. Fluid Mech., vol. 598, 2008, pp. 81–105; Kolvin et al.Phys. Rev. Lett., vol. 102, 2009, 014503), the conditions of the transition between the two mechanisms are less clear. We tackle this question experimentally by tracking the turbulent front away from a solid wall where jets enter an otherwise quiescent fluid. Without background rotation, this apparatus generates a turbulent front whose displacement recovers the law classically obtained with an oscillating grid (Dickinson & Long, Phys. Fluids, vol. 21 (10), 1978, pp. 1698–1701) and we further establish the scale independence of the associated transport mechanism. When the apparatus is rotating at a constant velocity perpendicular to the wall where fluid is injected, not only does the turbulent front become mainly transported by inertial waves, but advection itself is suppressed because of the local deficit of momentum incurred by the propagation of these waves. Scale-by-scale analysis of the displacement of the turbulent front reveals that the transition between advection and propagation is local both in space and spectrally, and takes place when the Rossby number based on the considered scale is of order unity, or equivalently, when the scale-dependent group velocity of inertial waves matched the local advection velocity

Régulation et performances de l’activité de dépollution : une analyse économétrique sur données individuelles

Nous décrivons dans cet article le mode de relation contractuelle existant entre une Agence de Bassin et des industriels polluants, et portant sur le financement de stations d’épuration. L’Agence de Bassin agit comme un régulateur vis-à-vis des industriels en fixant une taxe Pigouvienne sur les niveaux de pollution et en subventionnant les équipements d’épuration. L’un des objectifs de cet article est de préciser de façon quantitative le gain apporté par une régulation utilisant comme instrument alternatif une taxe personnalisée non linéaire. La fonction de dépollution des industriels est estimée en prenant en compte l’hétérogénéité des entreprises en matière de coût variable de dépollution. Les paramètres structurels ainsi estimés fournissent le point de départ d’une simulation d’un contrat virtuel avec taxe non linéaire, l’approche principal-agent étant utilisée comme cadre théorique. Les performances du contrat virtuel sont comparées à celles effectivement obtenues par la politique de taxe uniforme de l’Agence de Bassin.We describe in this paper the contract-based relation between a Water Agency and polluting industrials, for the financing of abatement plants. The Water Agency acts as a regulator with respect to industrials, by imposing a Pigouvian tax on effluent emissions and by subsidizing treatment equipments. One of the goals of this paper is to assess the benefit of using as an alternative regulatory instrument a personalized nonlinear tax. The abatement function of industrials is estimated, taking into account plant heterogeneity in terms of abatement variable cost. Estimated structural parameters form the basis of a simulation analysis of a virtual contract with a nonlinear emission tax, using the principal-agent paradigm as the theoretical framework. Performances of the virtual contract are compared to what is obtained by the Water Agency uniform tax policy