http://jasss.soc.surrey.ac.uk Journal of Artificial Societies and Social Simulation: For the exploration and understanding of social processes by means of computer simulation en-GB Copyright Journal of Artificial Societies and Social Simulation Thu, 04 Apr 2013 09:40:19 +0100 jasss@surrey.ac.uk (Nigel Gilbert) http://jasss.soc.surrey.ac.uk/gifs/JASSS-small.jpg http://jasss.soc.surrey.ac.uk warren.thorngate@rogers.com (Warren Thorngate and Bruce Edmonds) Article http://jasss.soc.surrey.ac.uk/16/2/4.html http://jasss.soc.surrey.ac.uk/16/2/4.html Sun, 31 Mar 2013 12:59:00 +0100 Warren Thorngate and Bruce Edmonds: Most traditional strategies of assessing the fit between a simulation's set of predictions (outputs) and a set of relevant observations rely either on visual inspection or squared distances among averages. Here we introduce an alternative goodness-of-fit strategy, Ordinal Pattern Analysis (OPA) that will (we argue) be more appropriate for judging the goodness-of-fit of simulations in many situations. OPA is based on matches and mismatches among the ordinal properties of predictions and observations. It does not require predictions or observations to meet the requirements of interval or ratio measurement scales. In addition, OPA provides a means to assess prediction-observation fits case-by-case prior to aggregation, and to map domains of validity of competing simulations. We provide examples to illustrate how OPA can be employed to assess the ordinal fit and domains of validity of simulations of share prices, crime rates, and happiness ratings. We also provide a computer programme for assisting in the calculation of OPA indices. tgulden@gmu.edu (Timothy R. Gulden) Article http://jasss.soc.surrey.ac.uk/16/2/1.html http://jasss.soc.surrey.ac.uk/16/2/1.html Sun, 31 Mar 2013 12:58:00 +0100 Timothy R. Gulden: This paper makes use of an agent-based framework to extend traditional models of comparative advantage in international trade, illustrating several cases that make theoretical room for industrial policy and the regulation of trade. Using an agent based implementation of the Hecksher-Ohlin trade model; the paper confirms Samuelson's 2004 result demonstrating that the principle of comparative advantage does not ensure that technological progress in one country benefits its trading partners. It goes on to demonstrate that the presence of increasing returns leads to a situation with multiple equilibria, where free market trading policies can not be relied on to deliver an outcome which is efficient or equitable, with first movers in development enjoying permanent advantage over later developing nations. Finally, the paper examines the impact of relaxation of the Ricardian assumption of capital immobility on the principle of comparative advantage. It finds that the dynamics of factor trade are radically different from the dynamics of trade in goods and that factor mobility converts a regime of comparative advantage into a regime of absolute advantage, thus obviating the reassuring equity results that stem from comparative advantage. ermanno.catullo@gmail.com (Ermanno Catullo) Article http://jasss.soc.surrey.ac.uk/16/2/7.html http://jasss.soc.surrey.ac.uk/16/2/7.html Sun, 31 Mar 2013 12:57:00 +0100 Ermanno Catullo: Export firms have better performance than firms that do not export, the so-called exporter premia: exporters are larger, they are relatively more capital and skill intensive, exporters have higher productivity (Bernard et al. 2007a; Bernard et al. 2005). The better performance of exporters may be the result of a self-selection effect: only the most competitive firms are able to enter foreign markets (ex-ante self-selection). On the other hand, exporting may improve firm performance (ex-post effect). Differences between exporters and non-exporters may have a significant impact on aggregate welfare and growth; in particular, disentangling the importance of the ex-ante effect from the ex-post effect may be useful for designing public policies (Bernard & Jensen 1999). The economic approach based on the Melitz (2003) model analyzes the exporter premia using monopolistic competition markets with firm heterogeneity in terms of a given distribution of firm productivity. This paper presents an agent based simulation of a monopolistic competition market in which firm heterogeneity is an emerging pattern of firms' choices and interactions, conceiving productivity growth as the results of firms' individual innovative efforts. The model is able to replicate the better performance of exporters, stressing the importance of decision-making processes and learning capabilities of firms in determining both the ex-ante and the ex-post effects. alessandro.pluchino@ct.infn.it (Alessio Emanuele Biondo, Alessandro Pluchino and Andrea Rapisarda) Article http://jasss.soc.surrey.ac.uk/16/2/11.html http://jasss.soc.surrey.ac.uk/16/2/11.html Sun, 31 Mar 2013 12:56:00 +0100 Alessio Emanuele Biondo, Alessandro Pluchino and Andrea Rapisarda: The Brain Drain phenomenon is particularly heterogeneous and is characterized by peculiar specifications. It influences the economic fundamentals of both the country of origin and the host one in terms of human capital accumulation. Here, the brain drain is considered from a microeconomic perspective: more precisely we focus on the individual rational decision to return, referring it to the social capital owned by the worker. The presented model compares utility levels to justify agent's migration conduct and to simulate several scenarios within a computational environment. In particular, we developed a simulation framework based on two fundamental individual features, i.e. risk aversion and initial expectation, which characterize the dynamics of different agents according to the evolution of their social contacts. Our main result is that, according to the value of risk aversion and initial expectation, the probability of return migration depends on their ratio, with a certain degree of approximation: when risk aversion is much bigger than the initial expectation, the probability of returns is maximal, while, in the opposite case, the probability for the agents to remain abroad is very high. In between, when the two values are comparable, it does exist a broad intertwined region where it is very difficult to draw any analytical forecast. a.ghorbani@tudelft.nl (Amineh Ghorbani, Pieter Bots, Virginia Dignum and Gerard Dijkema) Article http://jasss.soc.surrey.ac.uk/16/2/9.html http://jasss.soc.surrey.ac.uk/16/2/9.html Sun, 31 Mar 2013 12:55:00 +0100 Amineh Ghorbani, Pieter Bots, Virginia Dignum and Gerard Dijkema: In this paper we introduce and motivate a conceptualization framework for agent-based social simulation, MAIA: Modelling Agent systems based on Institutional Analysis. The MAIA framework is based on Ostrom's Institutional Analysis and Development framework, and provides an extensive set of modelling concepts that is rich enough to capture a large range of complex social phenomena. Developing advanced agent-based models requires substantial experience and knowledge of software development knowledge and skills. MAIA has been developed to help modellers who are unfamiliar with software development to conceptualize and implement agent-based models. It provides the foundation for a conceptualization procedure that guides modellers to adequately capture, analyse, and understand the domain of application, and helps them report explicitly on the motivations behind modelling choices. A web-based application supports conceptualization with MAIA, and outputs an XML file which is used to generate Java code for an executable simulation. maken1028@gmail.com (Yan Ma, Zhenjiang SHEN and Mitsuhiko Kawakami) Article http://jasss.soc.surrey.ac.uk/16/2/2.html http://jasss.soc.surrey.ac.uk/16/2/2.html Sun, 31 Mar 2013 12:54:00 +0100 Yan Ma, Zhenjiang SHEN and Mitsuhiko Kawakami: In recent decades, compact cities have become a new concern in urban planning in most Japanese cities. The main reason for this trend among Japanese cities is the phenomenon of de-urbanization and downtown decline that gradually occurred after the 1990s. As such, at present, there are dispersed, small, built-up portions of suburban areas that have resulted in household mobility outside the downtown. Therefore, some local governments in Japan are attempting to realize compact cities through policy intervention, such as encouraging households to relocate from suburban to downtown areas in order to address the population decline in urban areas. Recently, one such residential policy have been promoted by Japanese local city governments. By offering a local housing allowance, this policy encourages households to relocate to downtown areas. We developed an agent-based household residential relocation model (HRRM) to visualize the effect of this residential policy, that is, the local housing allowance. The HRRM is built on households’ adaptive behaviours and interactions through housing relocation choices and policy attitudes, and so it can simulate the diversified residential relocations of households in various lifecycle stages. Through simulation using the HRRM, the effectiveness of this residential policy can be visualized, and the HRRM will help local governments to understand the effects of residential policies. ykim@asu.edu (Yushim Kim, Wei Zhong and Yongwan Chun) Article http://jasss.soc.surrey.ac.uk/16/2/8.html http://jasss.soc.surrey.ac.uk/16/2/8.html Sun, 31 Mar 2013 12:53:00 +0100 Yushim Kim, Wei Zhong and Yongwan Chun: Public service delivery programs are not free from players' opportunistic behaviors, such as fraudulent benefit exchanges. The standard methods used to detect such misbehaviors are static, less effective in uncovering interactions between corrupt agents, and easy to evade because of corrupt agents' familiarity with detection procedures. Current fraud detection efforts do not match the dynamics and adaptive processes they are supposed to monitor and regulate. In this paper, an agent-based simulation model is built to gain insight on sanction choices to deter fraudulent activities in public service delivery programs. The simulation outputs demonstrate that sanctions with low certainty must be accompanied by prompt action in order to observe a reduction in fraudulent vendors. However, a similar level of reduction in fraudulent vendors may be achieved once a certain number of fraudulent vendors are sanctioned, even if the public agency's action is relatively delayed. These characteristics of sanctions provide strategic choices that public service delivery program managers can consider based on their priorities and resources. squazzon@eco.unibs.it (Flaminio Squazzoni and Claudio Gandelli) Article http://jasss.soc.surrey.ac.uk/16/2/3.html http://jasss.soc.surrey.ac.uk/16/2/3.html Sun, 31 Mar 2013 12:52:00 +0100 Flaminio Squazzoni and Claudio Gandelli: This paper investigates the impact of referee behaviour on the quality and efficiency of peer review. We focused on the importance of reciprocity motives in ensuring cooperation between all involved parties. We modelled peer review as a process based on knowledge asymmetries and subject to evaluation bias. We built various simulation scenarios in which we tested different interaction conditions and author and referee behaviour. We found that reciprocity cannot always have per se a positive effect on the quality of peer review, as it may tend to increase evaluation bias. It can have a positive effect only when reciprocity motives are inspired by disinterested standards of fairness. giabba@sfu.ca (Philippe Giabbanelli and Rik Crutzen) Article http://jasss.soc.surrey.ac.uk/16/2/10.html http://jasss.soc.surrey.ac.uk/16/2/10.html Sun, 31 Mar 2013 12:51:00 +0100 Philippe Giabbanelli and Rik Crutzen: Binge drinking is a complex social problem linked to an array of detrimental health effects. While binge drinking in youth has been analyzed extensively using traditional methods (e.g., regressions analyses), the adult population has received less attention, and recent work has exemplified the potential for simulations to help scholars and practitioners better understand the problem. In this paper, we used agent-based social network models to test a number of hypotheses on important aspects of binge drinking in a sample representative of the adult Dutch population. In particular, we found that a combination of simple social rules (choosing peers who are similar, being prompted to drink if at least a fraction of them drinks, and incorporating the context) was sufficient to correctly predict the behaviour of half of the binge drinkers and 4 out of 5 non binge drinkers. Furthermore, we used factorial analyses to examine the contribution and combination of hypotheses in predicting the behaviour of individuals, with results indicating that who we interact with may not matter so much as how we interact. Finally, we evaluated the potential for interventions that mediate interactions between people in order to reduce the prevalence of binge drinking and found that the impact of such interventions was non linear: moderate interventions would yield benefits, but stronger interventions may only be of limited further benefit. maxwell.leonard.brown@gmail.com (Maxwell Brown) Article http://jasss.soc.surrey.ac.uk/16/2/5.html http://jasss.soc.surrey.ac.uk/16/2/5.html Sun, 31 Mar 2013 12:50:00 +0100 Maxwell Brown: This research develops then merges two separate models to simulate electric vehicle diffusion through recreation of the Boston metropolitan statistical area vehicle market place. The first model is a mixed (random parameters) logistic regression applied to data from the US Department of Transportation's 2009 National Household Travel Survey. The second, agent-based model simulates social network interactions through which agents' vehicle choice sets are endogenously determined. Parameters from the first model are applied to the choice sets determined in the second. Results indicate that electric vehicles as a percentages of vehicle stock range from 1% to 22% in the Boston metropolitan statistical area in the year 2030, percentages being highly dependent on scenario specifications. A lower price is the main source of competitive advantage for vehicles but other characteristics, such as vehicle classification and range, are demonstrated to influence consumer choice. Government financial incentive availability leads to greater market shares in the beginning years and helps to spread diffusion in later years due to an increased base of initial adopters. Although seen as a potential hindrance to EV diffusion, battery cost scenarios have relatively small impacts on EV diffusion in comparison to policy, range, miles per gallon (MPG), and vehicle miles travelled (VMT) as a percentage of range assumptions. Pessimistic range assumptions decrease overall PHEV and BEV percentages of vehicle stock by 50% and 30%, respectively, relative to the EPA-estimated range scenarios. Fuel cost scenarios do not considerably alter estimated BEV and PHEV stock but increase the ratio of car stock to light truck stock in the internal combustion engine (ICE) vehicle spectrum. Specifically, cars are estimated at 55% of ICE vehicle stock in the default fuel price scenario but increase to 62% of ICE vehicle stock in the high world oil price scenario, with LTs covering the appropriate differences. yensheng.c@gmail.com (Yen-Sheng Chiang) Article http://jasss.soc.surrey.ac.uk/16/2/6.html http://jasss.soc.surrey.ac.uk/16/2/6.html Sun, 31 Mar 2013 12:49:00 +0100 Yen-Sheng Chiang: The investigation of how cooperation is achieved on graphs in the field of spatial game or network reciprocity has received proliferating attention in the biological and sociological literature. In line of the research, this paper provides an new account of how cooperation could evolve in complex networks when actors use information of network characteristics to strategize whether to cooperate or not. Different from past work that focuses exclusively on the evolution of unconditional cooperation, we are proposing new strategies that are choosy in whom to cooperate with, conditional on the structural attributes of the nodes occupied by actors. In a series of evolutionary tournaments conducted by computer simulation, the model shows that a pair of simple strategies-cooperating respectively with higher and lower nodal-attribute neighbors-can be advantageous in adaptive fitness when competing against unconditional cooperation and defection. In particular, these strategies of conditional cooperation work well in random graphs-a network known for being unfavorable to the selection of cooperation. This paper contributes to the literature by showing how network characteristics can serve as a mechanism to sustain cooperation in some hostile network environments where unconditional cooperation is unable to evolve. The cognitive foundations of the mechanism and its implications are discussed. karoly.takacs@uni-corvinus.hu (Károly Takács) Review http://jasss.soc.surrey.ac.uk/16/2/reviews/5.html http://jasss.soc.surrey.ac.uk/16/2/reviews/5.html Sun, 31 Mar 2013 12:48:00 +0100 Review of: Positive Linking: How Networks Can Revolutionise the World by Ormerod, Paul, reviewed by Károly Takács nronald@swin.edu.au (Nicole Ronald) Review http://jasss.soc.surrey.ac.uk/16/2/reviews/4.html http://jasss.soc.surrey.ac.uk/16/2/reviews/4.html Sun, 31 Mar 2013 12:47:00 +0100 Review of: Agent-Based Modelling of Socio-Technical Systems (Agent-Based Social Systems) by Dam, Koen H. van, Nikolic, Igor and Lukszo, Zofia (eds.), reviewed by Nicole Ronald c.e.garcia.diaz@gmail.com (Cesar Garcia-Diaz) Review http://jasss.soc.surrey.ac.uk/16/2/reviews/2.html http://jasss.soc.surrey.ac.uk/16/2/reviews/2.html Sun, 31 Mar 2013 12:46:00 +0100 Review of: Sociophysics: A Physicist's Modeling of Psycho-Political Phenomena (Understanding Complex Systems) by Galam, Serge, reviewed by Cesar Garcia-Diaz jbragin@ucla.edu (John Bragin) Review http://jasss.soc.surrey.ac.uk/16/2/reviews/7.html http://jasss.soc.surrey.ac.uk/16/2/reviews/7.html Sun, 31 Mar 2013 12:45:00 +0100 Review of: Social Self-Organization: Agent-Based Simulations and Experiments to Study Emergent Social Behavior (Understanding Complex Systems) by Helbing, Dirk (ed.), reviewed by John Bragin kovacsb@usi.ch (Balazs Kovacs) Review http://jasss.soc.surrey.ac.uk/16/2/reviews/1.html http://jasss.soc.surrey.ac.uk/16/2/reviews/1.html Sun, 31 Mar 2013 12:44:00 +0100 Review of: Complexity and Institutions: Markets, Norms and Corporations (International Economic Association) by Aoki, Masahiko, Binmore, Kenneth, Deakin, Simon and Gintis, Herbert (eds.), reviewed by Balazs Kovacs alberto.russo@univpm.it (Alberto Russo) Review http://jasss.soc.surrey.ac.uk/16/2/reviews/6.html http://jasss.soc.surrey.ac.uk/16/2/reviews/6.html Sun, 31 Mar 2013 12:43:00 +0100 Review of: Econophysics of Systemic Risk and Network Dynamics (New Economic Windows) by Abergel, Frédéric, Chakrabarti, Bikas K., Chakraborti, Anirban and Ghosh, Asim (eds.), reviewed by Alberto Russo