Preference stability along time: the time cohesiveness measure

This work introduces a non-traditional perspective about the problem of measuring the stability of agents’ preferences. Specifically, the cohesiveness of preferences at different moments of time is explored under the assumption of considering dichotomous evaluations. The general concept of time cohesiveness measure is introduced as well as a particular formulation based on the consideration of any two successive moments of time, the sequential time cohesiveness measure. Moreover, some properties of the novel measure are also provided. Finally, and in order to emphasize the adaptability of our proposal to real situations, a factual case of study about clinical decision-making is presented. Concretely, the study of preference stability for life-sustaining treatments of patients with advanced cancer at end of life is analysed. The research considers patients who express their opinions on three life-sustaining treatments at four consecutive periods of time. The novel measure provides information of patients preference stability along time and considers the possibility of cancer metastasesEste trabajo forma parte del proyecto de investigación con financiación nacional: MEC-FEDER Grant ECO2016-77900-

Managing Interacting Criteria: Application to Environmental Evaluation Practices

The need for organizations to evaluate their environmental practices has been recently increasing. This fact has led to the development of many approaches to appraise such practices. In this paper, a novel decision model to evaluate company’s environmental practices is proposed to improve traditional evaluation process in different facets. Firstly, different reviewers’ collectives related to the company’s activity are taken into account in the process to increase company internal efficiency and external legitimacy. Secondly, following the standard ISO 14031, two general categories of environmental performance indicators, management and operational, are considered. Thirdly, since the assumption of independence among environmental indicators is rarely verified in environmental context, an aggregation operator to bear in mind the relationship among such indicators in the evaluation results is proposed. Finally, this new model integrates quantitative and qualitative information with different scales using a multi-granular linguistic model that allows to adapt diverse evaluation scales according to appraisers’ knowledge

Reaching social consensus family budgets: The Spanish case

The study of family budgets has been traditionally used to analyse consumers’ behaviour and estimate cost-of-living since the end of 19th century. Generally speaking, the computation of the budgets has been based on two different methodologies, the prescriptive and the descriptive method. Both present several drawbacks like the comparison among different areas, family types and over time. This paper proposes a new methodology for reaching family budgets, namely social consensus family budgets, to overcome such problems and examine the main features of the novel approach. The suggested method uses the minimization of the differences with respect to the consumer’s preferences to obtain a solution that summarizes single behaviour into a social preference. This approach is especially conceived for preferences on possibly related-expenditure groups. In addition, several algorithms are introduced to compute the social family budgets. Finally, the contribution includes the Spanish case as an example of reaching some social consensus family budgets in order to show the operational character and intuitive interpretation of the proposal approach.Este trabajo forma parte del proyecto de investigación con financiación nacional: MEC-FEDER Grant ECO2016-77900-

Preferences stability: A measure of preferences changes over time

Producción CientíficaTraditionally, preferences have been considered stable although there are growing evidences that such stability is a mere theoretical assumption. Attending to this fact, it should be interesting to measure how much stability preferences provide in order to improve decision making processes. Surprisingly, no research has been found on measuring preferences stability. To overcome this drawback, this paper proposes a novel approach for measuring the stability of preferences and also for improving understanding of current and future decisions. In order to be faithful to reality, this research considers decisions like complete pre-orders on a set of alternatives. Following this reasoning, this paper provides the general concept of decision stability measure as well as two specific measures: the local and the global decision stability measure. Moreover, the main features of the novel approach are examined, including several mathematical results on the behaviour of the proposed measure. And eventually, this contribution develops two real cases of study, with in-depth analysis of preferences behaviour and their stability over time. Specifically, the first one explores into the characteristics of Spanish citizens' voting behaviour and the second one attempts to analyse European citizens' preferences about passenger car market.Este trabajo forma parte del proyecto de investigación con financiación nacional: MEC-FEDER Grant ECO2016-77900-

The problem of collective identity in a fuzzy environment

Producción CientíficaWe define the problem of group identication in a fuzzy environment. We concentrate on the case where the society is required to self-determine the belongingness of each member to a speci_c group, characterized by a single attribute. In general terms, this case consists of a collective identity issue that can be regarded as an aggregation problem of individual assessments within a group. Here we introduce the possibility that both the original assessments and the resulting output attach partial memberships to the collectivity, for each potential member. We propose relevant classes of rules, and some are axiomatically characterized. Our new approach provides a way to circumvent classical impossibility results like Kasher and Rubinstein's.Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178

A new measure of consensus with reciprocal preference relations: The correlation consensus degree

Producción CientíficaThe achievement of a ‘consensual’ solution in a group decision making problem depends on experts’ ideas, principles, knowledge, experience, etc. The measurement of consensus has been widely studied from the point of view of different research areas, and consequently different consensus measures have been formulated, although a common characteristic of most of them is that they are driven by the implementation of either distance or similarity functions. In the present work though, and within the framework of experts’ opinions modelled via reciprocal preference relations, a different approach to the measurement of consensus based on the Pearson correlation coefficient is studied. The new correlation consensus degree measures the concordance between the intensities of preference for pairs of alternatives as expressed by the experts. Although a detailed study of the formal properties of the new correlation consensus degree shows that it verifies important properties that are common either to distance or to similarity functions between intensities of preferences, it is also proved that it is different to traditional consensus measures. In order to emphasise novelty, two applications of the proposed methodology are also included. The first one is used to illustrate the computation process and discussion of the results, while the second one covers a real life application that makes use of data from Clinical Decision-Making.Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178

A new measure of consensus with reciprocal preference relations: The correlation consensus degree

Producción CientíficaThe achievement of a ‘consensual’ solution in a group decision making problem depends on experts’ ideas, principles, knowledge, experience, etc. The measurement of consensus has been widely studied from the point of view of different research areas, and consequently different consensus measures have been formulated, although a common characteristic of most of them is that they are driven by the implementation of either distance or similarity functions. In the present work though, and within the framework of experts’ opinions modelled via reciprocal preference relations, a different approach to the measurement of consensus based on the Pearson correlation coefficient is studied. The new correlation consensus degree measures the concordance between the intensities of preference for pairs of alternatives as expressed by the experts. Although a detailed study of the formal properties of the new correlation consensus degree shows that it verifies important properties that are common either to distance or to similarity functions between intensities of preferences, it is also proved that it is different to traditional consensus measures. In order to emphasise novelty, two applications of the proposed methodology are also included. The first one is used to illustrate the computation process and discussion of the results, while the second one covers a real life application that makes use of data from Clinical Decision-Making.Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178

Pairwise dichotomous cohesiveness measures

Producción CientíficaAbstract In a framework where experts or agents express their opinions in a dichotomous way, we analyze the cohesiveness of their opinions on axed set of issues in a population. A parametric family of related measures are introduced and axiomatically characterized. They are ordinally equivalent when the population isxed, and some further properties are proved. In order to argue that this restricted dichotomous situation is nevertheless versatile, the paper ends with several empirical illustrations based on real forecasts (for the 2012 American presidential election) and elections (with real data from referenda in two countries and from elections in several scientic societies).Ministerio de Economía, Industria y Competitividad (Project ECO2012-31933)Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178)Ministerio de Economía, Industria y Competitividad (Proyect CGL2008-06003-C03-03/CLI)Ministerio de Economía, Industria y Competitividad (Project CGL2011-29396-C03-02)

Public healthcare: Citizen’s preferences in Spain

Producción CientíficaThis paper analyzes the stability of citizens’ preferences on public healthcare services in Spain. Nowadays, the increasing privatization of some healthcare services and the rapid emergence of private hospitals have caused changes in people’s preferences on public healthcare systems. This paper focuses on analyzing the preferences of Spaniards on their healthcare system over time under the assumption that citizens’ preferences are represented by complete pre-orders. Data for this study were collected from the Spanish Health Barometer survey, and they were searched from 1995 until 2018. The results show that preferences on the public healthcare system are very stable along time

Hesitant Fuzzy Worth: an innovative ranking methodology for hesitant fuzzy subsets

Producción CientíficaWe introduce a novel methodology for ranking hesitant fuzzy sets. It builds on a recent, theoretically sound contribution in Social Choice. In order to justify the applicability of such analysis, we develop two real implementations: (i) new metarankings of world academic institutions that build on real data from three reputed agencies, and (ii) a new procedure for improving teaching performance assessments which we illustrate with real data collected by ourselves.Ministerio de Economía, Industria y Competitividad (Project ECO2012-31933)Ministerio de Economía, Industria y Competitividad (Project ECO2012-32178)Ministerio de Economía, Industria y Competitividad (Project CGL2008-06003-C03-03/CLI)Junta de Andalucía (Project P09-SEJ-05404