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on Discrete Choice Models |
| By: | Bo E. Honoré (Department of Economics, University of Princeton); Elie Tamer (Department of Economics, University of Princeton) |
| Abstract: | Identification of dynamic nonlinear panel data models is an important and delicate problem in econometrics. In this paper we provide insights that shed light on the identification of parameters of some commonly used models. Using this insight, we are able to show through simple calculations that point identification often fails in these models. On the other hand, these calculations also suggest that the model restricts the parameter to lie in a region that is very small in many cases, and the failure of point identification may therefore be of little practical importance in those cases. Although the emphasis is on identification, our techniques are constructive in that they can easily form the basis for consistent estimates of the identified sets. |
| JEL: | C23 C25 |
| Date: | 2002–10 |
| URL: | http://d.repec.org/n?u=RePEc:kud:kuieca:2004_23&r=dcm |
| By: | Mogens Fosgerau (Danish Transport Research Institute) |
| Abstract: | The distribution of the value of travel time savings (VTTS) is investigated employing various nonparametric techniques on a large, high quality data set. When background variables are not included in the model it is found that the right 13% tail of the distribution is not observed and hence the mean VTTS cannot be evaluated. This conclusion changes when background variables are introduced into a semiparametric model. A partially constrained Johnson SB distribution allowing evaluation of the mean VTTS is accepted against the nonparametric alternative and is preferred among 16 candidates for parametric VTTS distributions. The resulting mean VTTS is plausible but three times larger than the mean VTTS evaluated from a simple logit model and half as big as that arising from a model assuming a lognormal distribution for the VTTS. Such findings indicate the importance of properly accounting for the distribution when estimating the mean VTTS. The present findings may be used to guide the choice of mixing distribution in a mixed logit model. |
| Keywords: | value of travel time savings, time, transport, VTTS, distribution, nonparametric, semiparametric, Klein-Spady, Zheng, Johnson SB, lognormal |
| JEL: | R41 C14 C25 C91 |
| Date: | 2004–11–25 |
| URL: | http://d.repec.org/n?u=RePEc:wpa:wuwpur:0411006&r=dcm |
| By: | Thomas Bue Bjorner; Lars Garn Hansen; Clifford S. Russell (Department of Economics, Vanderbilt.edu) |
| Abstract: | Provision of information on the environmental effects of consumption is often put forward as an appealing alternative to traditional means of environmental regulation such as permits and environmental taxes. When consumers in opinion polls are asked if their purchasing decisions would be influenced by information on environmental or ethical aspects of products, the majority seem very ready to say yes. However, evidence for actual behavior along these lines is still limited. The paper presents an empirical analysis of the effect of a certified environmental label (the Nordic Swan), using a large Danish consumer panel with detailed information on actual purchases from the beginning of 1997 to January 2001 (weekly observations). In 1997, few products with the Nordic Swan label were available on the Danish market, as Denmark did not join the program of the other Nordic countries until April, 1997. Since then a considerable number of brands of different products in the Danish market have obtained the label, and the data includes information on purchases before and after a number of brands obtained the Swan label. In the paper we use a multinomial logit model to quantify the effect of the Swan label on consumers' choices among different brands of toilet paper, paper towels and detergents. It does appear that the Nordic Swan label has had a significant effect on Danish consumers' brand choices for toilet paper and detergents, corresponding to a willingness to pay for the certified environmental label of 10-17% of price of the labelled products. Results are less conclusive for paper towels, but the environmental label appears to have had less influence on the brand choice for the user of paper towels. . |
| Keywords: | Environmental labelling, information provision, consumer brand choice |
| JEL: | C25 D12 D64 Q28 |
| Date: | 2002–03 |
| URL: | http://d.repec.org/n?u=RePEc:van:wpaper:0203&r=dcm |
| By: | Bernard Monjardet (CERMSEM) |
| Abstract: | We first present the concept of duality appearing in order theory, i.e. the notions of dual isomorphism and of Galois connection. Then we describe two fundamental dualities, the duality extension/intention associated with a binary relation between two sets, and the duality between implicational systems and closure systems. Finally we present two "concrete" dualities occuring in social choice and in choice functions theories. |
| Keywords: | Antiexchange closure operator, closure system, Galois connection, implicational system, Galois lattice, path-independent choice function, preference aggregation rule, simple game |
| JEL: | C00 D71 |
| Date: | 2004–02 |
| URL: | http://d.repec.org/n?u=RePEc:mse:wpsorb:b04018&r=dcm |