The aim of this study is to analyze collaborations including agent-based modellers and policymakers to identify potential challenges that need to be overcome to facilitate simulation-based policy-making. To achieve this, we examined 18 publications reporting on joint projects where Agent-based modelling (ABM) was carried out in conjunction with modellers, policymakers, and other stakeholders to support policy-making. This study focuses on the challenges that modellers experienced during their collaboration e.g., disagreement about model specification, political obstacles, unrealistic expectations regarding the insights provided by ABM as well as the limitations of the models, and impatience of stakeholders when waiting for results. We identified and categorized these challenges into five themes: Challenges of Scope, Politics, Management, Understandability, and Credibility. These challenges were analyzed and used to formulate five recommendations, which are presented as a single approach that takes ethical considerations of policy modelling into account. So that these insights can be used to facilitate future simulation-based policy collaborations.

Social phenomena emerge from agent-environment interactions, rendering many statistical models unsuit-able. Agent-based Models (ABMs) offer a viable alternative for exploring policy implications. While recentcrises like the COVID-19 pandemic may have increased ABM awareness, their use in policy-making hasa long history. To better understand the potential challenges and opportunities of using ABMs to informpolicy-making, we conducted a systematic literature review and identified 34 articles describing the use ofABMs involving policymakers. This review revealed that ABMs have been implemented to support pol-icymakers across a range of policy areas, but also identified low levels of model traceability and formalcommunication. Moreover, the review showed that the model’s purpose and type tend to influence howvalidation is performed. The review concludes that models that have undergone little validation and lackproper documentation, while being informally communicated, may hinder policymakers from effectivelymotivating their decision-making.

This paper explores the topic of model credibility of Agent-based Models and how they should be evaluated prior to application in policy-making. Specifically, this involves analyzing bordering literature from different fields to: (1) establish a definition of model credibility -- a measure of confidence in the model's inferential capability -- and to (2) assess how model credibility can be strengthened through Verification, Validation, and Accreditation (VV&A) prior to application, as well as through post-application evaluation. Several studies have highlighted severe shortcomings in how V&V of Agent-based Models is performed and documented, and few public administrations have an established process for model accreditation. To address the first issue, we examine the literature on model V&V and, based on this review, introduce and outline the usage of a V&V plan. To address the second issue, we take inspiration from a practical use case of model accreditation applied by a government institution to propose a framework for the accreditation of ABMs for policy-making. The paper concludes with a discussion of the risks associated with improper assessments of model credibility. 

Agent-based models have long been argued a useful toolto support policy analysis, variably targeting the assessment of policydesign, as well as establishing its performance. Challenging, however,remains appropriate empirical parameterization and validation of suchmodels. This paper contributes to the development of rigorous accountsof policy modelling primarily driven by policy documents in order to develop general conceptual model. Such models can then serve as a basis forearly validation by subject matter experts, but more importantly, informthe subsequent inquiry relevant for the parameterization of such models, while at the same time offering the opportunity to detect deviationsfrom regulated practice. Relying on the scenario of organ donation basedon the Swedish legislation, we explore the merits of such an approach,and sketch the individual steps from policy documents to conceptualmodel. Supporting the methodological process, this paper employs theInstitutional Grammar 2.0, which offers selected features supporting theproposed modelling approach.