1,720,988 research outputs found
Binary choices in small and large groups: a unified model
No full textTwo different ways to model the diffusion of alternative choices within a population of individuals in the presence of social externalities are known in the literature. While Galam's model of rumors spreading considers a majority rule for interactions in several groups, Schelling considers individuals interacting in one large group, with payoff functions that describe how collective choices influence individual preferences. We incorporate these two approaches into a unified general discrete-time dynamic model for studying individual interactions in variously sized groups. We first illustrate how the two original models can be obtained as particular cases of the more general model we propose, then we show how several other situations can be analyzed. The model we propose goes beyond a theoretical exercise as it allows modeling Situations which are relevant in economic and social systems. We consider also other aspects such as the propensity to switch choices and the behavioral momentum, and show how they may affect the dynamics of the whole population
Nonlinearity in Economics and Social Science: The Outstanding Contributions of John Barkley Rosser Jr
No full textThe pioneering work of John Barkley Rosser Jr. (1948–2023) in various subfields of economics emphasizes the fact that economic and social phenomena are inherently nonlinear and often discontinuous. From this standpoint, Barkley has contributed substantially to a paradigm shift in economic theory and modelling. Both his influential research work and his unceasing survey work on different approaches and schools of thought in economics and social science, carried out through the lens of complexity theory, have succeeded to develop a broader view on economic thinking and continue to inspire many researchers worldwide. The articles in this issue cover a number of research areas and themes that were central to Barkley's work, from technological progress to evolutionary competition between firms, from regional science to income inequality, from environmental economics to more general macroeconomic themes, such as bubbles and crashes, financial instabilities and policy issues
Reaching consensus on rumors
Full text linkAn important contribution in sociophysics is the Galam's model of rumors spreading. This model provides an explanation of rumors spreading in a population and explains some interesting social phenomena such as the diffusion of hoaxes. In this paper the model has been reformulated as a Markov process highlighting the stochastic nature of the phenomena. This formalization allows us to derive conditions for consensus to be reached and for the existence of some interesting phenomena such as the emergence of impasses. The proposed formulation allows a deeper and more comprehensive analysis of the diffusion of rumors
Memory effects on binary choices with impulsive agents: Bistability and a new BCB structure
Full text linkAfter the seminal works by Schelling, several authors have considered models representing binary choices by different kinds of agents or groups of people. The role of the memory in these models is still an open research argument, on which scholars are investigating. The dynamics of binary choices with impulsive agents has been represented, in the recent literature, by a one-dimensional piecewise smooth map. Following a similar way of modeling, we assume a memory effect which leads the next output to depend on the present and the last state. This results in a two-dimensional piecewise smooth map with a limiting case given by a piecewise linear discontinuous map, whose dynamics and bifurcations are investigated. The map has a particular structure, leading to trajectories belonging only to a pair of straight lines. The system can have, in general, only attracting cycles, but the related periods and periodicity regions are organized in a complex structure of the parameter space. We show that the period adding structure, characteristic for the one-dimensional case, also persists in the two-dimensional one. The considered cycles have a symbolic sequence which is obtained by the concatenation of the symbolic sequences of cycles, which play the role of basic cycles in the bifurcation structure. Moreover, differently from the one-dimensional case, the coexistence of two attracting cycles is now possible. The bistability regions in the parameter space are investigated, evidencing the role of different kinds of codimension-two bifurcation points, as well as in the phase space and the related basins of attraction are described
PERIODIC CYCLES AND BIFURCATION CURVES FOR ONE-DIMENSIONAL MAPS WITH TWO DISCONTINUITIES
Full text linkGlobal dynamics in adaptive models of collective choice with social influence
No full textIn this chapter we present a unified approach for modelling the diffusion of alternative choices within a population of individuals in the presence of social externalities, starting from two particular discrete-time dynamic models Galam's model of rumors spreading [10] and a formalization of Schelling's binary choices [7]. We describe some peculiar properties of discrete-time (or event-driven) dynamic processes and we show how some long-rum (asymptotic) outcomes emerging from repeated short time decisions can be seen as emerging properties, sometimes unexpected, or difficult to be forecasted
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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