924 research outputs found
A Quantum-Conceptual Explanation of Violations of Expected Utility in Economics
The expected utility hypothesis is one of the building blocks of classical
economic theory and founded on Savage's Sure-Thing Principle. It has been put
forward, e.g. by situations such as the Allais and Ellsberg paradoxes, that
real-life situations can violate Savage's Sure-Thing Principle and hence also
expected utility. We analyze how this violation is connected to the presence of
the 'disjunction effect' of decision theory and use our earlier study of this
effect in concept theory to put forward an explanation of the violation of
Savage's Sure-Thing Principle, namely the presence of 'quantum conceptual
thought' next to 'classical logical thought' within a double layer structure of
human thought during the decision process. Quantum conceptual thought can be
modeled mathematically by the quantum mechanical formalism, which we illustrate
by modeling the Hawaii problem situation, a well-known example of the
disjunction effect, and we show how the dynamics in the Hawaii problem
situation is generated by the whole conceptual landscape surrounding the
decision situation.Comment: 9 pages, no figure
Learning to Generate Ambiguous Sequences
In this paper, we experiment with methods for obtaining
binary sequences with a random probability mass function and with low autocorrelation and use it to generate ambiguous outcomes.
Outputs from a neural network are mixed and shuffled, resulting in binary sequences whose probability mass function is non-convergent, constantly moving and changing.
Empirical comparison with algorithms that generate ambiguity shows that the sequences generated by the proposed method have a significantly lower serial dependence. Therefore, the method is useful in scenarios
where observes can see and record the outcome of each draw sequentially, by hindering the ability to make useful statistical inferences
Investment under ambiguity with the best and worst in mind
Recent literature on optimal investment has stressed the difference between the impact of risk and the impact of ambiguity - also called Knightian uncertainty - on investors' decisions. In this paper, we show that a decision maker's attitude towards ambiguity is similarly crucial for investment decisions. We capture the investor's individual ambiguity attitude by applying alpha-MEU preferences to a standard investment problem. We show that the presence of ambiguity often leads to an increase in the subjective project value, and entrepreneurs are more eager to invest. Thereby, our investment model helps to explain differences in investment behavior in situations which are objectively identical
Classical Logical versus Quantum Conceptual Thought: Examples in Economics, Decision theory and Concept Theory
Inspired by a quantum mechanical formalism to model concepts and their
disjunctions and conjunctions, we put forward in this paper a specific
hypothesis. Namely that within human thought two superposed layers can be
distinguished: (i) a layer given form by an underlying classical deterministic
process, incorporating essentially logical thought and its indeterministic
version modeled by classical probability theory; (ii) a layer given form under
influence of the totality of the surrounding conceptual landscape, where the
different concepts figure as individual entities rather than (logical)
combinations of others, with measurable quantities such as 'typicality',
'membership', 'representativeness', 'similarity', 'applicability', 'preference'
or 'utility' carrying the influences. We call the process in this second layer
'quantum conceptual thought', which is indeterministic in essence, and contains
holistic aspects, but is equally well, although very differently, organized
than logical thought. A substantial part of the 'quantum conceptual thought
process' can be modeled by quantum mechanical probabilistic and mathematical
structures. We consider examples of three specific domains of research where
the effects of the presence of quantum conceptual thought and its deviations
from classical logical thought have been noticed and studied, i.e. economics,
decision theory, and concept theories and which provide experimental evidence
for our hypothesis.Comment: 14 page
Quantum Experimental Data in Psychology and Economics
We prove a theorem which shows that a collection of experimental data of
probabilistic weights related to decisions with respect to situations and their
disjunction cannot be modeled within a classical probabilistic weight structure
in case the experimental data contain the effect referred to as the
'disjunction effect' in psychology. We identify different experimental
situations in psychology, more specifically in concept theory and in decision
theory, and in economics (namely situations where Savage's Sure-Thing Principle
is violated) where the disjunction effect appears and we point out the common
nature of the effect. We analyze how our theorem constitutes a no-go theorem
for classical probabilistic weight structures for common experimental data when
the disjunction effect is affecting the values of these data. We put forward a
simple geometric criterion that reveals the non classicality of the considered
probabilistic weights and we illustrate our geometrical criterion by means of
experimentally measured membership weights of items with respect to pairs of
concepts and their disjunctions. The violation of the classical probabilistic
weight structure is very analogous to the violation of the well-known Bell
inequalities studied in quantum mechanics. The no-go theorem we prove in the
present article with respect to the collection of experimental data we consider
has a status analogous to the well known no-go theorems for hidden variable
theories in quantum mechanics with respect to experimental data obtained in
quantum laboratories. For this reason our analysis puts forward a strong
argument in favor of the validity of using a quantum formalism for modeling the
considered psychological experimental data as considered in this paper.Comment: 15 pages, 4 figure
Reasons and Means to Model Preferences as Incomplete
Literature involving preferences of artificial agents or human beings often
assume their preferences can be represented using a complete transitive binary
relation. Much has been written however on different models of preferences. We
review some of the reasons that have been put forward to justify more complex
modeling, and review some of the techniques that have been proposed to obtain
models of such preferences
Resolving the Ellsberg Paradox by Assuming that People Evaluate Repetitive Sampling
Ellsberg (1961) designed a decision experiment where most people violated the axioms of rational choice. He asked people to bet on the outcome of certain random events with known and with unknown probabilities. They usually preferred to bet on events with known probabilities. It is shown that this behavior is reasonable and in accordance with the axioms of rational decision making if it is assumed that people consider bets on events that are repeatedly sampled instead of just sampled once
How brains make decisions
This chapter, dedicated to the memory of Mino Freund, summarizes the Quantum
Decision Theory (QDT) that we have developed in a series of publications since
2008. We formulate a general mathematical scheme of how decisions are taken,
using the point of view of psychological and cognitive sciences, without
touching physiological aspects. The basic principles of how intelligence acts
are discussed. The human brain processes involved in decisions are argued to be
principally different from straightforward computer operations. The difference
lies in the conscious-subconscious duality of the decision making process and
the role of emotions that compete with utility optimization. The most general
approach for characterizing the process of decision making, taking into account
the conscious-subconscious duality, uses the framework of functional analysis
in Hilbert spaces, similarly to that used in the quantum theory of
measurements. This does not imply that the brain is a quantum system, but just
allows for the simplest and most general extension of classical decision
theory. The resulting theory of quantum decision making, based on the rules of
quantum measurements, solves all paradoxes of classical decision making,
allowing for quantitative predictions that are in excellent agreement with
experiments. Finally, we provide a novel application by comparing the
predictions of QDT with experiments on the prisoner dilemma game. The developed
theory can serve as a guide for creating artificial intelligence acting by
quantum rules.Comment: Latex file, 20 pages, 3 figure
What factors are associated with recent intimate partner violence? findings from the WHO multi-country study on women's health and domestic violence
<p>Abstract</p> <p>Background</p> <p>Intimate partner violence (IPV) against women is a global public health and human rights concern. Despite a growing body of research into risk factors for IPV, methodological differences limit the extent to which comparisons can be made between studies. We used data from ten countries included in the WHO Multi-country Study on Women's Health and Domestic Violence to identify factors that are consistently associated with abuse across sites, in order to inform the design of IPV prevention programs.</p> <p>Methods</p> <p>Standardised population-based household surveys were done between 2000 and 2003. One woman aged 15-49 years was randomly selected from each sampled household. Those who had ever had a male partner were asked about their experiences of physically and sexually violent acts. We performed multivariate logistic regression to identify predictors of physical and/or sexual partner violence within the past 12 months.</p> <p>Results</p> <p>Despite wide variations in the prevalence of IPV, many factors affected IPV risk similarly across sites. Secondary education, high SES, and formal marriage offered protection, while alcohol abuse, cohabitation, young age, attitudes supportive of wife beating, having outside sexual partners, experiencing childhood abuse, growing up with domestic violence, and experiencing or perpetrating other forms of violence in adulthood, increased the risk of IPV. The strength of the association was greatest when both the woman and her partner had the risk factor.</p> <p>Conclusions</p> <p>IPV prevention programs should increase focus on transforming gender norms and attitudes, addressing childhood abuse, and reducing harmful drinking. Development initiatives to improve access to education for girls and boys may also have an important role in violence prevention.</p
Mechanisms of Psychological Distress following War in the Former Yugoslavia: The Role of Interpersonal Sensitivity
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This study was funded by a grant from the European Commission, contract number INCO-CT-2004-509176. AN was supported by a Clinical Early Career Research Fellowship (113295) and a Project Grant (104288
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