
on Utility Models and Prospect Theory 
By:  Denis Conniffe (Economics, National University of Ireland, Maynooth); 
Abstract:  The idea that probability distribution functions could provide appropriate mathematical forms for utility functions representing risk aversion is of respectable antiquity. But the relatively few examples that have appeared in the economics literature have displayed quite restrictive risk aversion properties. This paper examines the potential of the generalised extreme value (GEV) distribution as utility function, showing it possesses considerable flexibility as regards risk aversion properties, even in its single parameter form. The paper concludes that the GEV utility function is worth considering for applications in cases where parametric parsimony matters. 
Date:  2007 
URL:  http://d.repec.org/n?u=RePEc:may:mayecw:n1780907&r=upt 
By:  Christopher L. Gilbert; Francesca Modena 
Abstract:  Textbook discussions of discrete choice modelling focus on binomial and multinomial choice models in which agents select a single response. We consider the situation of nonexclusive multinomial choice. The widely used Marginal Logit Model imposes independence and has other disadvantages. We propose two models which account for nonexclusive and dependent multiple responses and require at least one response. In the first and simpler specification, the Poissonmultinomial, households first choose the number of responses to a specific shock, and then the specific choices are identified to maximize household utility conditional on the former choice. The second specification, the thresholdmultinomial, generalizes the standard multinomial logit model by supposing that agents will choose more than one response if the utility they derive from other choices is “close” to that of the utilitymaximizing choice. We apply these two approaches to reported responses of rural Indonesian rural households to demographic and economic shocks. 
Keywords:  Discrete choice models, Marginal logit, Shocks, Risk coping strategies 
JEL:  C25 C51 O12 
Date:  2007 
URL:  http://d.repec.org/n?u=RePEc:trn:utwpde:0724&r=upt 
By:  Elchanan BenPorath 
Abstract:  The paper analyzes an economy with asymmetric information in which agents trade in contingent assets. The new feature in the model is that each agent may have any prior belief on the states of nature and thus the posterior belief of an agent maybe any probability distribution that is consistent with his private information. We study two solution concepts: Equilibrium, which assumes rationality and market clearing, and common knowledge equilibrium (CKE) which makes the stronger assumption that rationality, market clearing, and the parameters which de?ne the economy are common knowledge. The two main results characterize the set of equilibrium prices and the set of CKE prices in terms of parameters which specify for each state s and event E the amount of money in the hands of agents who know the event E at the state s. The characterizations that are obtained apply to a broad class of preferences which include all preferences that can be represented by the expectation of a state dependent monotone utility function. One implication of these results is a characterization of the information that is revealed in a CKE. 
Date:  2007–06 
URL:  http://d.repec.org/n?u=RePEc:huj:dispap:dp462&r=upt 
By:  ReynaldAlexandre Laurent 
Abstract:  This paper proposes a discrete choice duopoly in which products are described and differentiated by their specific attributes. These attributes can be discrete characteristics or differences in continuous variables, such as prices or qualities. Consumers follow a probabilistic reasoning which is consistent with random decision rule models such as Tversky's "Elimination by Aspects" framework (1972a,b). This type of behavior is relevant for small everyday life purchases. The demand system provides a general structure of product differentiation in which special cases are given by classical models of horizontal and vertical differentiation. Existence and uniqueness of a price Nash equilibrium in pure strategies are established in the duopoly. When attributes' utilities vary, comparative statics properties of profits can be explained by "attractiveness" and "differentiation" effects. These effects are combined in a new way compared to the deterministic structures or to the logit duopoly. For example, an increase in the low utility index of attributes strengthens product differentiation. 
Date:  2007 
URL:  http://d.repec.org/n?u=RePEc:pse:psecon:200727&r=upt 