940 research outputs found
The Core of a Coalitional Production Economy Without Ordered Preferences
It is shown that the core of a coalitional production economy with a balanced technology (Bohm [1974]) is nonempty, even if the consumers have preferences which are intransitive, provided the preferences are convex and continuous. Since such preferences cannot be represented by utility functions, this result does not follow from the nonemptiness of the core of a characteristic function game. Rather, the approach is closer to that of Ichiishi's [1981] social coalitional equilibrium
Reduced Form Auctions Revisited
This note uses Farkas’s Lemma to prove new results on the implementability of general, asymmetric auctions, and to provide simpler proofs of known results for symmetric auctions. The tradeoff is that type spaces are taken to be finite
On Equilibria of Excess Demand Correspondences
A new lemma on the existence of maximal elements of binary relations is proved and applied to a revealed preference relation on price vectors. The resulting maximal elements are equilibrium prices. This technique allows one to generalize results of Aliprantis and Brown [1982], Neuefeind [1980], and Geistdoerfer-Florenzano [1982]
An Impossibility Theorem for Spatial Models
This paper examines the implications for social welfare functions of restricting the domain of individual preferences lo type-one preferences. Type-one preferences assume that each person has a most preferred alternative in a euclidean space and that alternatives are ranked according to their euclidean distance from this point. The result is that if we impose Arrow's conditions of collective rationality, IIA, and the Pareto principle on the social welfare function, then it must be dictatorial. This result may not seem surprising, but it stands in marked contrast to the problem considered by Gibbard and Saiterthwaite of finding a social-choice function. With unrestricted domain, under the Gibbard-Satterthwaite hypotheses, choices must be dictatorial. With type-one preferences this result has been previously shown not to be true. This finding identifies a significant difference between the Arrow and the Gibbard-Satterwaite hypothesis
Social Welfare Functions for Economic Environments with and without the Pareto Principle
Social welfare functions for private goods economies with classical preferences are considered. It is shown that every social welfare function satisfying a weak nonimposition condition and the independence of irrelevant alternatives axiom is of one of the following forms. It is either null or the class of decisive coalitions is an ultrafilter or the class of anti-decisive coalitions is an ultrafilter
More on Harsanyi's Utilitarian Cardinal Welfare Theorem
If individuals and society both obey the expected utility hypothesis and social alternatives are uncertain, then the social utility must be a linear combination of the individual utilities, provided the society is indifferent when all its members are. This result was first proven by Harsanyi [4] who made implicit assumptions in the proof not actually needed for the result (see [5]). This note presents a straightforward proof of Harsanyi's theorem based on a separating hyperplane argument
Variability of δ234U in the Mediterranean Sea, Amazon Estuary, and Atlantic Ocean
It has long been assumed that the world's oceans are homogeneous in δ234U, even on a sub-‰ scale, however this has not been comprehensively investigated outside of the North Pacific using modern high-precision MC-ICP-MS. In this study, the δ234U of water samples from across the Mediterranean Sea, Amazon Estuary, and North Atlantic is presented to show that the oceanic uranium system is much more variable and dynamic than previously believed and variable on a ‰-scale. Mediterranean water masses are elevated in δ234U compared to the Atlantic by ~1-2‰, allowing for the estimation of the δ234U of riverine and groundwater inputs to the basin. Analysis within the Amazon Estuary shows that there are significant geographical differences in the non-conservative behavior of U, and that the Amazon has little to no effect on the δ234U of the nearby Atlantic. The upper Atlantic is on average 1‰ lower in δ234U than the deep Atlantic, indicating that oceanic δ234U is not in steady-state but rather decreasing. Results point towards the offset seen in the upper Atlantic possibly being the result of inputs from the Indian Ocean (which has yet to be investigated at such high-precision), indicating that such oceanic δ234U variability may be a widespread phenomena
Spacecraft-spacecraft very long baseline interferometry. Part 1: Error modeling and observable accuracy
In Part 1 of this two-part article, an error budget is presented for Earth-based delta differential one-way range (delta DOR) measurements between two spacecraft. Such observations, made between a planetary orbiter (or lander) and another spacecraft approaching that planet, would provide a powerful target-relative angular tracking data type for approach navigation. Accuracies of better than 5 nrad should be possible for a pair of spacecraft with 8.4-GHz downlinks, incorporating 40-MHz DOR tone spacings, while accuracies approaching 1 nrad will be possible if the spacecraft incorporate 32-GHz downlinks with DOR tone spacing on the order of 250 MHz; these accuracies will be available for the last few weeks or months of planetary approach for typical Earth-Mars trajectories. Operational advantages of this data type are discussed, and ground system requirements needed to enable spacecraft-spacecraft delta DOR observations are outlined. This tracking technique could be demonstrated during the final approach phase of the Mars '94 mission, using Mars Observer as the in-orbit reference spacecraft, if the Russian spacecraft includes an 8.4-GHz downlink incorporating DOR tones. Part 2 of this article will present an analysis of predicted targeting accuracy for this scenario
Noncooperative Games, Abstract Economies, and Walrasian Equilibria
The introduction of an additional player to serve as coordinator in an N-person abstract economy leads in a natural way to an N+1-person noncooperative game. Sufficient conditions on the abstract economy are considered which lead to the existence of equilibrium in the resulting game and hence for the abstract economy
A Core Existence Theorem for Games Without Ordered Preferences
[Introduction] To a large extent the cooperative theory of games has an altogether different
appearance from the noncooperative theory. The noncooperative theory generally deals
with games in either extensive form or normal form, while the cooperative theory is usually
described in characteristic function form. One of the central concepts in the cooperative
theory is that of the core, which is the set of utility allocations which no coalition can
improve upon. This notion of the core and of the characteristic function form of a game
depends heavily on the existence of a utility representation for players' preferences. Recently
Gale and Mas-Colell [3] and Shafer and Sonnenschein [6] have proven theorems on the
existence of a Nash equilibrium for noncooperative games in normal form in which the
players' preferences over strategy vectors are not necessarily complete or transitive and
so may fail to have a utility representation. Thus it might appear that the noncooperative
theory is applicable in environments where the cooperative theory is not. In order to
formulate theorems in the cooperative theory of games which can be applied to environments
in which players may have nonordered preferences, the characteristic function must
be reformulated in terms of physical outcomes as opposed to utility outcomes. The players'
preferences can then be expressed in terms of the physical outcomes without the use of
a utility function
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