We propose a novel approach to the statistical analysis of simulation models and, especially, agent-based models (ABMs). Our main goal is to provide a fully automated and model-independent tool-kit to inspect simulations and perform counterfactual analysis. Our approach: (i) is easy-to-use by the modeller, (ii) improves reproducibility of results, (iii) optimizes running time given the modeller's machine, (iv) automatically chooses the number of required simulations and simulation steps to reach user-specified statistical confidence, and (v) automatically performs a variety of statistical tests. In particular, our framework is designed to distinguish the transient dynamics of the model from its steady-state behaviour (if any), estimate properties of the model in both "phases", and provide indications on the ergodic (or non-ergodic) nature of the simulated processes -- which, in turns allows one to gauge the reliability of a steady-state analysis. Estimates are equipped with statistical guarantees, allowing for robust comparisons across computational experiments. To demonstrate the effectiveness of our approach, we apply it to two models from the literature: a large scale macro-financial ABM and a small scale prediction market model. Compared to prior analyses of these models, we obtain new insights and we are able to identify and fix some erroneous conclusions.
翻译:我们提出对模拟模型,特别是代理模型进行统计分析的新办法。我们的主要目标是提供一个完全自动化和完全依赖模型的工具基,以检查模拟并进行反事实分析。我们的方法是:(一) 易于模型者使用,(二) 改进结果的再复制,(三) 优化模型机器的运行时间,(四) 自动选择必要的模拟和模拟步骤的数量,以达到用户指定的统计信心,(五) 自动进行各种统计测试。特别是,我们的框架旨在将模型的短暂动态与其稳定状态行为(如果有的话)区分开来,在“阶段”中估计模型的特性,并指明模拟过程的紧急(或非紧急)性质 -- -- 这反过来又使得人们能够衡量稳定状态分析的可靠性。估计具有统计保证,能够进行各种计算实验。为了表明我们的方法的有效性,我们将其应用于两个模型的短暂动态与其稳定状态行为(如果有的话)区分,在“阶段”中估计模型的特性,并在“阶段”中提供模型的属性,同时说明模型的特征(或非紧急的)性质 -- -- 反过来衡量稳定状态分析的可靠性,我们就能在进行新的计算试验中进行新的统计分析。我们把模型应用于两个模型用于以往的精确的模型和精确的模型。