Abstract

From a microeconomic viewpoint, the so-called modal utility in discrete choice models is a conditional indirect utility function, which represents the maximum level of satisfaction that can be reached at given prices and income if a particular mode was chosen;. Therefore, its functional form represents implicitly, or explicitly, the analytical solution of an optimisation problem, thus, both the specification of direct utility (variables and form) and the type of constraints considered determine the specification of modal utility. In this chapter, the: main issues behind the formulation of a general microeconomic model of users behaviour are discussed. The model is motivated by, and contrasted against, other forms of representing the primal problem of individual behaviour, coming either from the microeconomic literature on thr role of rims in consumer's behaviour (Becker, 1965; DeSerpa, 1971; Evans, 1972), or from the approaches that yield, or discuss mode choice models with a microeconomic perspective (McFadden, 1981; Train and McFadden, 1978; Viton, 1985; Truong and Hensher, 1985; Bares, 1987; Jara-Diaz and Farah, 1987). The implications of the new:formulation on actual modelling under different assumptions are presented and discussed.