A note on preference for flexibility

A result of Kreps (1979) on preference for flexibility is extended from two to three periods (formally from preferences over sets to preferences over sets of sets). An intuitively easier route to Kreps' original result is also presented, making the proof essentially ready for use in a decision theory class. Received: 23 April 2001 / Accepted: 1 September 2001 First version October 1997.     

A note on the clarke and shrestha linear space model

This note re-examines two important propositions in the Clarke and Shrestha linear space model. We provide a complete analysis of designing and locating a secondary energy generation facility in the Clarke and Shrestha linear model and clarify two of their propositions.     

On the multi-utility representation of preference relations

We develop the ordinal theory of (semi)continuous multi-utility representation for incomplete preference relations. We investigate the cases in which the representing sets of utility functions are either arbitrary or finite, and those cases in which the maps contained in these sets are required to be (semi)continuous. With the exception of the case where the representing set is required to be finite, we find that the requirements of such representations are surprisingly weak, pointing to a wide range of applicability of the representation theorems reported here. Some applications to decision theory under uncertainty and consumer theory are also considered.     

Variable preference relations: Existence of maximal elements

We consider variable preference relations, also called reference dependent preference relations, which are typical in the study of dynamic models in economic theories. We introduce a new concept of weak consistency, a generalization of acyclicity, as an immediate regret condition for variable preferences. The main result to establish is on an existence criterion for maximal elements of a space equipped with a weakly consistent variable preference relation. It is expressed via a preference completeness condition which is equivalent to existence of aspiration points. As applications, we show that a number of results known in the recent literature on maximum principles on a space with or without topological structure can be obtained from the unifying approach of this paper. Habit formation and state functions are also discussed in the framework of variable preference relations.     

Essential supremum and essential maximum with respect to random preference relations

In the first part of the paper, we study concepts of supremum and maximum as subsets of a topological space X$X$ endowed by preference relations. Several rather general existence theorems are obtained for the case where the preferences are defined by countable semicontinuous multi-utility representations. In the second part of the paper, we consider partial orders and preference relations “lifted” from a metric separable space X$X$ endowed by a random preference relation to the space L⁰(X)$L^0\left(X\right)$ of X$X$-valued random variables. We provide an example of application of the notion of essential maximum to the problem of the minimal portfolio super-replicating an American-type contingent claim under transaction costs.     

A note on the microeconomics of migration

"The purpose of this note is to demonstrate in a simple model that an individual's migration from a small town to a large city may be rationalized purely by a consumption motive, rather than the motive of obtaining a higher income. More specifically, it is shown that in a large city an individual may derive a higher utility from spending a given amount of income than in a small town." A formal model is first developed that includes the principal forces at work and is then illustrated using a graphic example. The theoretical and empirical issues raised are considered in the concluding section.     

A note on redistribution

A consequence of income redistribution may well be to make everyone (including lower-income groups to which redistribution takes place) worse off after a period of years. Possibly income redistribution might gain consent because of risk aversion. The paper also draws attention to the tendency for people to be more concerned about poverty close at hand rather than far away.     

A note on the optimality ofk-stage tests

Summary This note deals with sequential tests requiring at mostk observations. First a lemma is proved concerning the form of Bayes solutions. Then it is demonstrated by giving a counter-example that the theorem ofWald andWolfowitz has no correspondence fork-stage tests.

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Zusammenfassung Es wird gezeigt, daß man beik-stufigen Tests zwar für die Gestalt vonBayes-Lösungen ein Analogon zu den unbeschränkten Sequenztests hat, daß aber der Satz vonWald undWolfowitz über die gleichmäßige Optimalität bzgl. des Stichprobenumfangs keine Entsprechung besitzt.

     

A note on the determinants of residential succession

A recent paper by J. Brueckner [J. Urban Econ., 4, (1977)] presents empirical evidence that the Muth vintage model explains the neighborhood succession process better than the Bailey boundary externality model. This note shows that Brueckner's apparent empirical findings are spurious as a result of the construction of the dependent variable, and do not provide insight into the neighborhood succession process. Re-estimation of the corrected regressions using similar data yields results which are clearly supportive of neither theoretical model.     

A note on the length of the black-white border

Two simple models of racial prejudice and household location predict that the black area in a city will be of the shape that minimizes the length of the black-white border. This note provides a way to test these models by showing, for a variety of assumptions about urban structure, that in a city with a population more than about 10% black, the black-white border will be shorter if the black area is wedge-shaped than if it is circular.     

A note on minimum variance

Summary Minimizing is discussed under the unbiasedness condition: and the condition (A):f _i (x) (i=1, ..., p) are linearly independent , and .     

A note on linked bargaining

A recent result by Jackson and Sonnenschein (2007) describes a general framework for overcoming incentive constraints by linking together independent copies of a Bayesian decision problem. A special case of that work shows that if copies of a standard two-player Bayesian bargaining problem are independently linked (players receive valuations and trade simultaneously on a number of identical copies), then the utility cost associated with incentive constraints tends to 0 as the number of linked problems tends to infinity. We improve upon that result, increasing the rate of convergence from polynomial to exponential and eliminating unwanted trades in the limit, by introducing a mechanism that uses a slightly richer and more refined strategy space. Although very much in the same spirit, our declarations are constrained by a distribution which is skewed away from the expected distribution of player types. When a sufficiently large number of bargaining problems are linked, “truth” is an equilibrium. Moreover, this equilibrium is incentive compatible with the utility cost of incentive constraints almost surely equal to 0.     

A note on the uniform distribution on the arcsin points

In his book Pukelsheim [8] pointed out that designs supported at the arcsin points are very efficient for the statistical inference in a polynomial regression model. In this note we determine the canonical moments of a class of distributions which have nearly equal weights at the arcsin points. The class contains theD-optimal arcsin support design and theD ₁-optimal design for a polynomial regression. The results allow explicit representations ofD-, andD ₁-efficiencies of these designs in all polynomial models with a degree less than the number of support points of the design.     

A note on characterization by the conditional expectation

Summary Various distributions like exponential, Pareto, power and Burr's distribution are characterized in terms of conditional expectation of a functionh (·) of the absolutely continuous random variable.