Horizontal and Vertical Multiple Implementations in a Model of Industrial Districts

In this paper we discuss strategies concerning the implementation of an agent-based simulation of complex phenomena. The model we consider accounts for population decomposition and interaction in industrial districts. The approach we follow is twofold: on one hand, we implement progressively more complex models using different approaches (vertical multiple implementations); on the other hand, we replicate the agent-based simulation with different implementations using jESOF, JAS and plain C++ (horizontal multiple implementations). By using both different implementation approaches and a multiple implementation strategy, we highlight the benefits that arise when the same model is implemented on radically different simulation environments, comparing the advantages of multiple modeling implementations. Our findings provide some important suggestions in terms of model validation, showing how models of complex systems tend to be extremely sensitive to implementation details. Finally we point out how statistical techniques may be necessary when comparing different platform implementations of a single model.Replication of Models; Model Validation; Agent-Based Simulation

The role of incomplete information and others' choice in reducing traffic: a pilot study

In this study, we investigate the role of payoff information and conformity in improving networkperformance in a traffic dilemma known as the Braess paradox. Our goal is to understand whendecisions are guided by selfish motivations or otherwise by social ones. For this purpose, weconsider the manipulation of others’ choice, public and private monitoring and information ondistribution of choices. Data show that when social comparison was not salient, participantswere more cooperative. By contrast, cooperativeness of others’ choice made participants morecompetitive leading to traffic and collective performance decrease. The implications of these findingsto the literature on social dilemmas are discussed