Regular Effective Demand Systems (REDS)

Empirical demand analysis is usually conducted on the basis of either ‘regularity’ or ‘flexibility’. This paper takes a middle ground between ‘regularity’ and ‘flexibility’, offering a compromise in the form of a new specification termed ‘REDS’.     

Errors of aggregation and errors of specification in a consumer demand model: a theoretical note

Abstract .  Consumer demand models based on the concept of a representative or average consumer suffer from aggregation error. Misspecification of the underlying micro utility-maximizing model, which is virtually inevitable, also results in error. This note provides a theoretical investigation of the relationship between the two types of error. Misspecified expenditure support functions for demand systems at the micro level induce the same misspecified structure in the corresponding expenditure functions at the macro level, and the errors at the two levels are shown to be of similar order.     

Commitment and self-control

The literature on self-control problems has typically concentrated on immediate temptations. This paper studies a Gul and Pesendorfer [Temptation and self-control, Econometrica 69 (2001) 1403-1435; Self-control and the theory of consumption, Econometrica 72 (2004) 119-158] style model in which decision-makers are affected by temptations that lie in the future. While temptation is commonly understood to give rise to a demand for commitment, it is shown that ‘temptation by future consumption’ can induce its absence. The model also exhibits procrastination, provides an alternative to projection bias as an explanation for some experimental results, and can simultaneously account for myopic and hyperopic behavior. The evidence on preference reversals supports temptation by future consumption, and suggests that it may not be restricted to short time horizons.     

Context effects: A representation of choices from categories

This paper studies a model of reference-dependent choice from sets of options grouped into categories. The proposed model is consistent with experimental evidence documenting context effects in a variety of choice situations. In our model, the reference point for any given category is subjective, and corresponds to the least preferred element in the category under consideration. Every object in a category is evaluated relative to the corresponding reference point; this may distort the objective ranking of options across different categories, and thus possibly give rise to a context-effects bias. The resulting representation is essentially unique. We also provide an economic application of the preferences that we axiomatize to principal-agent models. We show how sellers facing consumers exhibiting the context-effects bias can increase their profits by exploiting their bounded rationality.     

On Giffen-like goods

This paper provides, as a counter example to the Alchian-Allen theorem, a theory of Giffen-like goods: a per unit charge to two similar goods raises the relative price of the lower quality good and yet increases the (relative) demand of the good.     

A note on small income effects

This note provides an alternative sufficient condition for the small income effect result that is first shown by Vives [Small income effects: a Marshallian theory of consumer surplus and downward sloping demand, Rev. Econ. Stud. 54(1) (1987) 87-103]. The condition is stated by ordinal terms only, whereas Vives assumes cardinal properties of utility representation. Second, as its application, we provide a sufficient condition for the preference being asymptotically quasi-linear, in a two good economy where the second good is a composition of a large number of goods.     

Preference for Flexibility and Dynamic Consistency

Dekel, Lipman, and Rustichini [3] characterize preferences over menus of lotteries that can be represented by the use of a unique subjective state space and a prior. We investigate what would be the appropriate version of Dynamic Consistency in such a setup. The condition we find, which we call Flexibility Consistency, is linked to a comparative theory of preference for flexibility. When the subjective state space is finite, we show that Flexibility Consistency is equivalent to a subjective version of Dynamic Consistency and that it implies that the decision maker is a subjective state space Bayesian updater. Later we characterize when a collection of signals can be interpreted as a partition of the subjective state space of the decision maker.     

A systematic analysis of the links amongst the Marshallian,Hicksian, and Frischian demand functions: A note

Three types of demand functions are central to contemporary consumer theory: the Marshallian, the Hicksian, and the Frischian demand functions. This paper presents a systematic definition of the analytical relationships amongst these demand functions under the maintained hypothesis that the decision maker is a profit maximizer.     

A theory of (relative) discounting

We derive a representation theorem for time preferences (on the prize-time space) which identifies a novel notion of relative discounting as the key ingredient. This representation covers a variety of time preference models, including the standard exponential and hyperbolic discounting models and certain non-transitive time preferences, such as the similarity-based and subadditive discounting models. Our axiomatic work thus unifies a number of seemingly disparate time preference structures, thereby providing a tractable mathematical format that allows for investigating certain economic environments without subscribing to a particular time preference model. This point is illustrated by means of an application to sequential bargaining theory.     

Expected utility theory without the completeness axiom

We study the problem of obtaining an expected utility representation for a potentially incomplete preference relation over lotteries by means of a set of von Neumann-Morgenstern utility functions. It is shown that, when the prize space is a compact metric space, a preference relation admits such a multi-utility representation provided that it satisfies the standard axioms of expected utility theory. Moreover, the representing set of utilities is unique in a well-defined sense.     

A class of incomplete and ambiguity averse preferences

This paper characterizes models of ambiguous beliefs in the absence of the completeness axiom. We axiomatize multiple-selves versions of some of the most important examples of complete and ambiguity averse preferences, and characterize when those incomplete preferences are ambiguity averse.     

Small worlds: Modeling attitudes toward sources of uncertainty

We introduce the concept of a conditional small world event domain—an extension of Savage's [The Foundations of Statistics, Wiley, New York, 1954] notion of a ‘small world’—as a self-contained collection of comparable events. Under weak behavioral conditions we demonstrate probabilistic sophistication in any small world event domain without relying on monotonicity or continuity. Probabilistic sophistication within, though not necessarily across, small worlds provides a foundation for modeling a decision maker that has source-dependent risk attitudes. This also helps formalize the idea of source preference and suggests an interpretation of ambiguity aversion, often associated with Ellsberg-type behavior, in terms of comparative risk aversion across small worlds.     

Supermodularity and preferences

We uncover the complete ordinal implications of supermodularity on finite lattices under the assumption of weak monotonicity. In this environment, we show that supermodularity is ordinally equivalent to the notion of quasisupermodularity introduced by Milgrom and Shannon. We conclude that supermodularity is a weak property, in the sense that many preferences have a supermodular representation.     

Removed preferences

In formalizing a ‘veil of ignorance’ type procedure, this paper considers how an agent?s preferences over a set of alternatives change as he is placed at an increasing ‘distance’ from the consequences of his choices. A definition for such ‘removed preferences’ is presented and its properties studied. As an application, it is demonstrated that present biased agents are ‘essentially’ exponential when distanced from the present, and that rank-dependent expected utility agents are ‘essentially’ expected utility when distanced from risk.     

Effective global regularity and empirical modelling of direct, inverse, and mixed demand systems

Abstract .  This paper utilizes the notion of 'effective global regularity' and the intuition stemming from Cooper and McLaren (1996)'s General Exponential Form to develop a family of 'composite' (product and ratio) direct, inverse and mixed demand systems. Apart from having larger regularity regions, the resulting specifications are also of potentially arbitrary rank, which can better approximate non-linear Engel curves. We also make extensive use of duality theory and a numerical inversion estimation method to rectify the endogeneity problem encountered in the estimation of the mixed demand systems. We illustrate the techniques by estimating different types of demand systems for Japanese quarterly meat and fish consumption.