A Survey of Agent-Based Modeling Practices (January 1998 to July 2008)

In the 1990s, Agent-Based Modeling (ABM) began gaining popularity and represents a departure from the more classical simulation approaches. This departure, its recent development and its increasing application by non-traditional simulation disciplines indicates the need to continuously assess the current state of ABM and identify opportunities for improvement. To begin to satisfy this need, we surveyed and collected data from 279 articles from 92 unique publication outlets in which the authors had constructed and analyzed an agent-based model. From this large data set we establish the current practice of ABM in terms of year of publication, field of study, simulation software used, purpose of the simulation, acceptable validation criteria, validation techniques and complete description of the simulation. Based on the current practice we discuss six improvements needed to advance ABM as an analysis tool. These improvements include the development of ABM specific tools that are independent of software, the development of ABM as an independent discipline with a common language that extends across domains, the establishment of expectations for ABM that match their intended purposes, the requirement of complete descriptions of the simulation so others can independently replicate the results, the requirement that all models be completely validated and the development and application of statistical and non-statistical validation techniques specifically for ABM.Agent-Based Modeling, Survey, Current Practices, Simulation Validation, Simulation Purpose

Strategic ambiguity and risk in alternating pie-sharing experiments

We experimentally study a class of pie-sharing games with alternating roles from a decision-making perspective. For this, we consider a variant of a two-stage alternating-offer game which introduces an imbalance in the protagonists’ bargaining powers. This game class enables us to investigate how exposure to risk and strategic ambiguity affects one’s bargaining behaviour. Two structural econometric models of behaviour, a naïve and a sophisticated one, capture remarkably well the observed deviations from the game-theoretic benchmark. Our findings indicate, in particular, that a higher exposure to strategic ambiguity leads to a behaviour that is less responsive to the game’s parameters and to distorted, yet consistent, beliefs about other’s behaviour. We also find evidence of a backward-reasoning whereby first-stage decisions relate to the second-stage ones but which do not call for the counterfactual reasoning that characterises rationality in such settings