873 research outputs found
Interview with Jacqueline DeGroot
No full textJacqueline DeGroot, author of Climax and Worth Any Price, discusses how she came to be a writer, her writing process and sources of inspiration, and her experiences with self-publishing
Private Valuation of a Public Good in Three Auction Mechanisms.
No full textWe evaluate the impact of three auction mechanisms – the Becker–DeGroot–Marschak (BDM) mechanism, the second-price auction (SPA), and the random nth-price auction (NPA) – in the measurement of private willingness-to-pay and willingness-to-accept for a pure public good. Our results show that the endowment effect is lower with the BDM mechanism. In this market mechanism, the effect disappears after a few repetitions. Yet, on a logarithmic scale, the random nth-price auction yields the highest speed of convergence towards equality of welfare indices. We also observe that subjects value public goods in reference to their private subjective benefit derived from their public good funding.auction mechanisms; WTP-WTA disparity; private provisions; public goods;
The Asynchronous DeGroot Dynamics
No full textWe analyze the asynchronous version of the DeGroot dynamics: In a connected
graph with nodes, each node has an initial opinion in and an
independent Poisson clock. When a clock at a node rings, the opinion at
is replaced by the average opinion of its neighbors. It is well known that the
opinions converge to a consensus. We show that the expected time to reach -consensus is poly in
undirected graphs and in Eulerian digraphs, but for some digraphs of bounded
degree it is exponential.
Our main result is that in undirected graphs and Eulerian digraphs, if the
degrees are uniformly bounded and the initial opinions are i.i.d., then
for every fixed
. We give sharp estimates for the variance of the limiting
consensus opinion, which measures the ability to aggregate information
(``wisdom of the crowd''). We also prove generalizations to non-reversible
Markov chains and infinite graphs. New results of independent interest on
fragmentation processes and coupled random walks are crucial to our analysis
Convergence rate of the modified DeGroot-Friedkin model with doubly stochastic relative interaction matrices
No full textIn a recent paper [1], a modified DeGroot-Friedkin model was proposed to study the evolution of the social-confidence levels of individuals in a reflected appraisal mechanism in which a network of n individuals consecutively discuss a sequence of issues. The individuals update their self-confidence levels on one issue in finite time steps, via communicating with their neighbors, instead of waiting until the discussion on the previous issue reaches a consensus, while the neighbor relationships are described by a static relative interaction matrix. This paper studies the same modified DeGroot-Friedkin model, but with time-varying interactions which are characterized by a sequence of doubly stochastic matrices. It is shown that, under appropriate assumptions, the n individuals' self-confidence levels will all converge to 1 n exponentially fast. An explicit expression of the convergence rate is provided.</p
On a Modified DeGroot-Friedkin Model of Opinion Dynamics
No full textA social network typically consists of two components: a collection of social
actors (individuals, groups of people or organizations) and a description of
the connections among those actors. Within a social network, the
interactions among actors are capable of spreading and influencing the
opinions.
Consequently, one's opinion is not merely formed by himself or herself, but is
also affected by the opinions of others through interactions. How much one
trusts his or her own opinion and how much one is willing to accept others'
opinions both depend on the self-confidence level of the particular social actor.
This thesis studies the opinion dynamics that result when individuals
consecutively discuss a sequence of issues. Specifically, we study how individuals' self-confidence levels evolve via a reflected appraisal mechanism, which
in simple words, describes the phenomenon that individuals' self-appraisals
on some dimension (e.g., self-confidence, self-esteem) are influenced
by the
appraisals of other individuals on them. Motivated by the DeGroot-Friedkin
model, we propose a Modified DeGroot-Friedkin model which allows individuals to update their self-confidence levels by only interacting with their
neighbors and in particular, the modified model allows the update of self-
confidence levels to take place in finite time without waiting for the opinion
process to reach a consensus on any particular issue. We study properties of
this Modified DeGroot-Friedkin model and compare the associated equilibria
and stability with those of the original DeGroot-Friedkin model. Specifically,
for the case when the interaction matrix is doubly stochastic, we show that
for the modified model, the vector of individuals' self-confidence levels converges to a unique nontrivial equilibrium which for each individual is equal
to 1/n,
where n is the number of individuals. This implies that eventually
individuals reach a democratic state.Submitted by Janice Progen ([email protected]) on 2015-07-31T16:03:59Z
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Previous issue date: 2015-05Ope
An experimental study of wine consumers’ willingness to pay for environmental characteristics
No full textThe reduction of pesticides use is becoming a priority for the public authorities in many countries. We conducted an experiment with wine consumers to see whether end-consumers value the dissemination of information about environmentally-friendly production practices. The experiment was devised to (i) evaluate whether there is a premium for environmentally-friendly wines, (ii) determine whether or not consumers are sensitive to label owners who implement and guarantee the environmental actions, (iii) and assess the impact of public messages about the consequences of pesticide use. Some 139 participants were divided randomly into two groups. One group had no specific information about the current state of pesticide use in farming. The other group was given information about pesticide use in farming before making their valuations. Becker-DeGroot-Marshak mechanisms revealed that (i) the environmental signal is valued differently depending on who conveyed the information, and that (ii)dissemination of information about the environmental repercussions of farming methods does not significantly affect willingness-to-pay.Willingness to pay, Wine, Effect of information, Experimental economics, Environment, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety,
Opinion Formation in Social Networks
No full textA number of selected works on the dynamics of opinions and beliefs in social networks has been discussed. Both Bayesian and non-Bayesian approaches to social learning have been considered, but the analysis has been focused on a simple, tractable and widely used model of updating beliefs - the DeGroot model. The author studied the dynamics of opinions based on the DeGroot model from different points of view. First, its attractive features and shortcomings were discussed and then some of its extensions have been presented. These models are based on the DeGroot updating rule, but addition-ally incorporate the possibility of improvements and enrichments of the framework. (original abstract
Social Preferences and Voting: An Exploration Using a Novel Preference Revealing Mechanism
No full textPublic referenda are frequently used to determine the provision of public goods. As public programs have distributional consequences, a compelling question is what role if any social preferences have on voting behavior. This paper explores this issue using laboratory experiments wherein voting outcomes lead to a known distribution of net benefits across participants. Preferences are elicited using a novel Random Price Voting Mechanism (RPVM), which is a more parsimonious mechanism than dichotomous choice referenda, but gives consistent results. Results suggest that social preferences, in particular a social efficiency motive, lead to economically meaningful deviations from self-interested voting choices and increase the likelihood that welfare-enhancing programs are implemented.Institutional and Behavioral Economics, Research Methods/ Statistical Methods, C91, C92, D64, D72, H41,
Scotland and Dementia Research
No full textdementia researchScotlanddementia carehome careCanadaResearch Infographics - Faculty of Health and Faculty of Arts. Kwantlen Polytechnic University (KPU) researchers/instructors Carol Hansen, Judith DeGroot and Sharon Leitch travelled to Scotland to learn about its national strategic dementia plan and review current research
Irreversibility, Uncertainty, and Cyclical Investment
No full textThe optimal timing of real investment is studied under the assumptions that investment is irreversible and that new information about returns is arriving over time. Investment should be undertaken in this case only when the costs of deferring the project exceed the expected value of information gained by waiting. Uncertainty, because it increases the value of waiting for new information, retards the current rate of investment. The nature of investor's optimal reactions to events whose implications are resolved over time is a possible explanation of the instability of aggregate investment over the business cycle.
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