39 research outputs found
Consistency of crisp and fuzzy preference relations
In this paper we point out some difficulties in developing rationality measures of fuzzy preference relations, as defined by Cutello and Montero in a previous paper. In particular, we analyze some alternative approaches, taking into account that consistency can not be viewed as an univoque concept in a fuzzy framework, neither in the crisp context, where consistency should not be necessarily represented in terms of linear orders
Fuzzy and probabilistic choice functions: a new set of rationality conditions
IFSA-EUSFLAT'2015: 16th World Congress of the International Fuzzy Systems Association and 9th Conference of the European Society for Fuzzy Logic and Technlogy, July 2015, GijĂłn, SpainProbabilistic and fuzzy choice theory are used to describe decision situations in which a certain degree of imprecision is involved. In this work we propose a correspondence between probabilistic and fuzzy choice functions, based on implication operators. Given a probabilistic choice function a fuzzy choice function can be constructed and, furthermore, a new set of rationality conditions is proposed. Finally, we prove that under those conditions, the associated fuzzy choice function fulfills desirable rationality propertie
Fuzzy and probabilistic choice functions : a new set of rationality conditions
Probabilistic and fuzzy choice theory are used to describe decision situations in which a certain degree of imprecision is involved. In this work we propose a correspondence between probabilistic and fuzzy choice functions, based on implication operators. Given a probabilistic choice function a fuzzy choice function can be constructed and, furthermore, a new set of rationality conditions is proposed. Finally, we prove that under those conditions, the associated fuzzy choice function fulfills desirable rationality properties
Bridging probabilistic and fuzzy approaches to choice under uncertainty
Imprecise choices can be described using either a probabilistic or a fuzzy formalism. No relation between them has been studied so far. In this contribution we present a connection between the two formalisms that strongly makes use of fuzzy implication operators and t-norms. In this framework, Luce's Choice Axiom turns out to be a special case when the product t-norm is considered and other similar choice axioms can be stated, according to the t-norm in use. Also a new family of operators for transforming bipolar relations into unipolar ones is presented
MayorĂas basadas en diferencias: análisis de la consistencia y extensiones
En esta tesis se estudian las mayorĂas por diferencia de votos y por diferencia de apoyo. Los capĂtulos 1 y 2 se centran en el análisis de la transitividad y de la triple-aciclicidad de la relaciĂłn de preferencia fuerte generada por las mayorĂas por diferencia de apoyo, al agregar relaciones de preferencia recĂprocas individuales. En el capĂtulo 3 se estiman las probabilidades con las que se producen resultados colectivos consistentes, tanto en las mayorĂas por diferencia de apoyo como en las mayorĂas por diferencia de votos. En el capĂtulo 4 se extienden las mayorĂas por diferencia de votos al contexto de las preferencias lingĂĽĂsticas, a travĂ©s de conjuntos difusos y del modelo de las 2-tuplas; se justifica la equivalencia entre ambas modelizaciones bajo determinadas condiciones de regularidad y se estudian las propiedades que cumplen estas mayorĂas lingĂĽĂsticasDepartamento de EconomĂa Aplicad
Houthakker and Ville's contributions to demand theory: a new look at the debate on integrability conditions.
Jean Ville gave, independently of Houthakker, and prior to him, a general one page proof of the integrability of demand functions in a revealed preference scheme. It happens that this essential contribution has been largely ignored in the literature. The comparison between Ville and Houthakker’s proofs makes room for discussing the assumptions necessary to encompass the discrete version of the acyclicity into a continuous version.
Causal Effects in Matching Mechanisms with Strategically Reported Preferences
A growing number of central authorities use assignment mechanisms to allocate
students to schools in a way that reflects student preferences and school
priorities. However, most real-world mechanisms give students an incentive to
be strategic and misreport their preferences. In this paper, we provide an
identification approach for causal effects of school assignment on future
outcomes that accounts for strategic misreporting. Misreporting may invalidate
existing point-identification approaches, and we derive sharp bounds for causal
effects that are robust to strategic behavior. Our approach applies to any
mechanism as long as there exist placement scores and cutoffs that characterize
that mechanism's allocation rule. We use data from a deferred acceptance
mechanism that assigns students to more than 1,000 university-major
combinations in Chile. Students behave strategically because the mechanism in
Chile constrains the number of majors that students submit in their preferences
to eight options. Our methodology takes that into account and partially
identifies the effect of changes in school assignment on various graduation
outcomes
Towards a Model of Argument Strength for Bipolar Argumentation Graphs
UID/FIL/00183/2013Bipolar argument graphs represent the structure of complex pro and contra arguments for one or more standpoints. In this article, ampliative and exclusionary principles of evaluating argument strength in bipolar acyclic argumentation graphs are laid out and compared to each other. Argument chains, linked arguments, link attackers and supporters, and convergent arguments are discussed. The strength of conductive arguments is also addressed but it is argued that more work on this type of argument is needed to properly distinguish argument strength from more general value-based components of such argu- ments. The overall conclusion of the article is that there is no justifiably unique solution to the problem of argument strength outside of a particular epistemological framework.publishersversionpublishe
Desire, belief, and conditional belief
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Linguistics and Philosophy, 2008.Includes bibliographical references (leaves 127-132).This dissertation studies the logics of value and conditionals, and the question of whether they should be given cognitivist analyses. Emotivist theories treat value judgments as expressions of desire, rather than beliefs about goodness. Inference ticket theories of conditionals treat them as expressions of conditional beliefs, rather than propositions. The two issues intersect in decision theory, where judgments of expected goodness are expressible by means of decision-making conditionals. In the first chapter, I argue that decision theory cannot be given a Humean foundation by means of money pump arguments, which purport to show that the transitivity of preference and indifference is a requirement of instrumental reason. Instead, I argue that Humeans should treat the constraints of decision theory as constitutive of the nature of preferences. Additionally, I argue that transitivity of preference is a stricter requirement than transitivity of indifference. In the second chapter, I investigate whether David Lewis has shown that decision theory is incompatible with anti-Humean theories of desire. His triviality proof against "desire as belief' seems to show that desires can be at best conditional beliefs about goodness. I argue that within causal decision theory we can articulate the cognitivist position where desires align with beliefs about goodness, articulated by the decision making conditional. In the third chapter, I turn to conditionals in their own right, and especially iterated conditionals.(cont.) I defend the position that indicative conditionals obey the import-export equivalence rather than modus ponens (except for simple conditionals), while counterfactual subjunctive conditionals do obey modus ponens. The logic of indicative conditionals is often thought to be determined by conditional beliefs via the Ramsey Test. I argue that iterated conditionals show that the conditional beliefs involved in indicative supposition diverge from the conditional beliefs involved in learning, and that half of the Ramsey Test is untenable for iterated conditionals.by David Jeffrey Etlin.Ph.D