Yves Croissant

University of Reunion Island · Department of Economics

Hurdle regression models are regression models where the dependent variable is left censored at zero, which is typically the case in household expenditure surveys. These models are of particular interest to explain the presence of a large proportion of zero observations for the dependent variable by means of censoring mechanisms, called hurdles. Fo...

In this paper we revisit some issues related to the use of the Box-Cox transformation in censored and truncated regression models, which have been overlooked by the econometric and statistical literature. We first analyze the shape of the density function of the random variable which, rescaled by a Box-Cox transformation, leads to a normal random v...

mlogit is a package for R which enables the estimation of random utility models with choice situation and/or alternative specific variables. The main extensions of the basic multinomial model (heteroscedastic, nested and random parameter models) are implemented.

World fragmentation of production and demand differentiation on CGE model: a methodological proposal Implementing a development strategy in the context of a fragmented global strategy consists in specializing in the production of a specific link of the value chain. Yet, modelling this strategy within the framework of a computable general equilibriu...

The application of personal carbon trading (PCT) to transport choices has recently been considered in the literature as a means of reducing CO2 emissions. Its potential effectiveness in changing car travel behavior is compared to the conventional carbon tax (CT) by means of a stated preferences survey conducted among French drivers (N ∼ 300). We sh...

Allotment is, for urban authorities, a governance strategy to reduce public transport costs. It consists of dividing a network into several lots, so as to multiply the number of calls for tender. On the one hand, gains should be obtained by increasing competition for the market and reducing the costs of obtaining accurate information. On the other...

Various methods of restricting automobile traffic, by price (tolls) or by quantity (odd/even license plates or limited days of traffic), are tested in a survey (N ∼ 400) about attitudes toward traffic restrictions in Lyon, France. Ordered probit models with random-effects panel allow us to estimate the survey respondents’ perceptions of these metho...

Urban Toll and (un)Fairness: an Obstacle to an Experimentation in France ? With an attitude survey in Lyon, we test different principles of rationing car traffic by prices (road toll) or by quantities (odd numbers or reduced day of travelling). Rationing by price or by quantity is strongly perceived as unfair by responders. Attitudes towards tolls...

Model formulas are the standard approach for specifying the variables in statistical models in the S language. Although being eminently useful in an extremely wide class of applications, they have certain limitations including being confined to single responses and not providing convenient support for processing formulas with multiple parts. The la...

The perceived fairness of different rules for allocating scarce resources is analysed in two cases: seats on a high speed train and parking spaces in a company car park. Attitudes toward allocation rules depend on context. They vary according to: the educational level of respondents; the type of “good”; and the exceptional or recurring nature of sc...

We have developed a method to obtain robust quantitative bibliometric indicators for several thousand scientists. This allows us to study the dependence of bibliometric indicators (such as number of publications, number of citations, Hirsch index...) on the age, position, etc. of CNRS scientists. Our data suggests that the normalized h-index (h div...

Most scientific institutions acknowledge the importance of opening the so-called 'ivory tower' of academic research through popularization, industrial collaboration or teaching. However, little is known about the actual openness of scientific institutions and how their proclaimed priorities translate into concrete measures. This paper gives an idea...

We have developed a method to obtain robust quantitative bibliometric indicators for several thousand scientists. This allows us to study the dependence of bibliometric indicators (such as number of publications, number of citations, Hirsch index...) on the age, position, etc. of CNRS scientists. Our data suggests that the normalized h index (h div...

Today, most scientific institutions acknowledge the importance of opening the so-called "ivory tower" of academic research through popularization, industrial innovation or teaching. However, little is known about the actual openness of scientific institutions and how their proclaimed priorities translate into concrete measures. This paper helps get...

This introduction to the plm package is a slightly modified version of Croissant and Millo (2008), published in the Journal of Statistical Software. Panel data econometrics is obviously one of the main fields in the profession, but most of the models used are difficult to estimate with R. plm is a package for R which intends to make the estimation...

Recently, some cities decided to divide their transport network into several attractive and accessible parts (this procedure is called allotment) in order to reduce urban transit costs. Gains obtained by introducing more competition for the market should be compared with costs associated with cutting the network into several parts, and this questio...

In order to reduce their public transport costs, some cities want to multiply the number of call for tender they organise, by dividing their network in sev-eral lots ("allotment"). In terms of costs-benefit analysis, gains obtained by in-troducing more competition for the market should be compared with the in-creasing transaction costs. But cutting...

We have analyzed the popularization activities undertaken by ten thousand CNRS researchers by means of their annual reports for the years 2004, 2005 and 2006. This is the first time that such an extensive statistical study on science popularization practices is carried out. Our main findings are : - the majority of researchers is not involved in po...

We have analyzed the popularization activities undertaken by ten thousand CNRS researchers by means of their annual reports for the years 2004, 2005 and 2006. This is the first time that such an extensive statistical study on science popularization practices is carried out. Our main findings are : - the majority of researchers is not involved in po...

R est un Logiciel libre, qui est un dialecte de S, langage de programmation pour les analyses statistiques développé dans les années 80 aux laboratoires Bell, en particulier par John Chambers. R a été écrit initialement par Ross Ihaka et Robert Gentleman et est actuellement développé par une petite équipe de développeurs (R Core Development Team)....

Le projet ETHEL vise à : - simuler les conséquences –au plan de la consommation d’énergie et d’émission de GES– d’hypothèses sociétales et technologiques sur l’évolution des modes de vie, des localisations d’activités, des types de logements associés, des offres de transports et des comportements de déplacements associés ; - en produisant des indic...

Une grande partie des politiques de développement repose sur l'envoi de transferts aux économies connaissant des difficultés de développement. Si ces aides semblent favorables au bien être des agents, leurs effets sur la croissance de long terme des économies restent ambigus ou parfois décevants. L'objectif de cet article est de contribuer à mieux...

Une grande partie des politiques de d�veloppement repose sur l'envoi de transferts aux �conomies connaissant des difficult�s de d�veloppement. Si ces aides semblent favorables au bien �tre des agents, leurs effets sur la croissance de long terme des �conomies restent ambigus ou parfois d�cevants. L'objectif de cet article est de contribuer � mieux...

The aim of this paper is to evaluate the consequences of the reform of the local enterprise tax on labour supply. The purpose of this reform is to increase labour supply by exempting wages from the tax. Results show that the effects of the reform crucially depend on factor substitution possibilities and on the production reaction to a cost decrease...

Fonction de demande et surplus : une estimation sur des données de panel pour les transports urbains français par Yves Croissant Cet article présente l'estimation d'une fonction de demande pour les transports urbains. Il s'agit d'une fonction de type translog qui prend en compte la distribution des revenus et qui est estimée sur données de panel fr...

form of the multinomial logit model is implemented in R, with individual-specic variables, with the multinom function in the nnet package. We provide a package called mlogit which enables the estimation of the multinomial logit model with both individual and alternative specic variables. Several packages currently in development that depends on mlo...

mhurdle is a package for R enabling the estimation of a wide set of models for which the response is zero left-censored. This kind of models are called limited dependent or Tobit models in the econometric literature and are of particular interest to analyze households' consumption data provided by family expenditure surveys.

In France, 90% of the urban authorities use to delegate the production of public transport services to a single operator. And the last 10% carry on a direct management (régie municipale). The coexistence of several operators is very uncommon, while several European cities work with more than one partner. Those local authorities (London, Stockholm…)...