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About this book

Simulating for a crisis is far more than creating a simulation of a crisis situation. In order for a simulation to be useful during a crisis, it should be created within the space of a few days to allow decision makers to use it as quickly as possible. Furthermore, during a crisis the aim is not to optimize just one factor, but to balance various, interdependent aspects of life. In the COVID-19 crisis, decisions had to be made concerning e.g. whether to close schools and restaurants, and the (economic) consequences of a 3 or 4-week lock-down had to be considered. As such, rather than one simulation focusing on a very limited aspect, a framework allowing the simulation of several different scenarios focusing on different aspects of the crisis was required. Moreover, the results of the simulations needed to be easily understandable and explainable: if a simulation indicates that closing schools has no effect, this can only be used if the decision makers can explain why this is the case. This book describes how a simulation framework was created for the COVID-19 crisis, and demonstrates how it was used to simulate a wide range of scenarios that were relevant for decision makers at the time. It also discusses the usefulness of the approach, and explains the decisions that had to be made along the way as well as the trade-offs. Lastly, the book examines the lessons learned and the directions for the further development of social simulation frameworks to make them better suited to crisis situations, and to foster a more resilient society.

Table of Contents


ASSOCC Theory and Platform


Chapter 1. Introduction

The introduction of this book sets the stage of performing social simulations in a crisis. The contents of the book are based on the experience of creating a large scale and complex social simulation for the Covid-19 crisis. However, the contents are reaching much further than just this experience. We will show the general contribution that social simulations based on fundamental social-psychological principles can have in times of crises. In times of big societal changes due to a pandemic or other disaster, these simulations can give handles to support decision makers in their difficult task to act in a very short time with many uncertainties. Besides giving our results, we also will indicate why the results are trustworthy and interesting. Finally we also look what challenges should be picked up to convert the successful project into a sustainable research area.
Frank Dignum, Loïs Vanhée, Maarten Jensen, Christian Kammler, René Mellema, Fabian Lorig, Cezara Păstrăv, Mijke van den Hurk, Alexander Melchior, Amineh Ghorbani, Bart de Bruin, Kurt Kreulen, Harko Verhagen, Paul Davidsson

Chapter 2. Foundations of Social Simulations for Crisis Situations

Simulating human behaviour in times of crisis requires models of human decision that are include aspects beyond directly visible actions. In crisis times the behaviour of people will change based on the changing environment and needs. Without an underlying model that can represent how and when people will change their behaviour it becomes difficult to incorporate these behavioural changes in the simulation. In this chapter we will introduce the foundations of the model that we used to model the human behaviour for the Covid-19 crisis. We argue that these foundations are not only useful for this application but are broadly applicable for simulations that need to capture behavioural change due to crises or other external influences.
Frank Dignum

Chapter 3. Social Simulations for Crises: From Theories to Implementation

This chapter describes how the general theories presented in the previous chapter have been used for the concrete ASSOCC software platform, which is used as the basis for all the scenarios described in Chaps. 510. We will describe the agent architecture and deliberation mechanism based on the needs. We also will introduce the environment which is modelled like a small town in which the agents live. The chapter also describes the epistemiological model that we use to represent the COVID-19 disease specific elements.
Maarten Jensen, Loïs Vanhée, Christian Kammler

Chapter 4. Social Simulations for Crises: From Models to Usable Implementations

Simulations created for crises naturally have two important goals: the simulation must both be sound and solid from a scientific standpoint, but also should be exploitable at very short notice by stakeholders in the decision-support of the crisis. A central activity of building simulations during crises is conducting an advanced software project, for which implementing the central simulation model is only one of the many tasks. Taking a systems-design perspective, this chapter describes the needs, concerns, and solutions for achieving the goals raised by simulations during crises by illustrating how they were addressed by the ASSOCC software platform within the project. In particular, ASSOCC goes beyond classic social simulation standards by incorporating dedicated visualisation aspects, leading to an architecture that combines a simulation module (in NetLogo), a visualisation module (in Unity) and an analysis module (in R). This chapter explains what modules were required and for which purpose, what outcome to expect from developing such modules, and how to design and implement such a module and overarching architecture to interact with one another.
Cezara Păstrăv, Maarten Jensen, René Mellema, Loïs Vanhée



Chapter 5. The Effectiveness of Closing Schools and Working at Home During the COVID-19 Crisis

In this chapter we show the results of simulations of two widely adopted measures that were taken in order to stop the spreading of the Covid-19 virus, namely closing of schools and working from home. We take these two measures together because in practice they are often instated together and at least parents with young children will have to stay at home if the children cannot go to school. We will simulate different scenarios in order to separately examine the effects of closed schools and people working from home on the number of infections, hospitalisations and social contacts, and the effect of the combination of the two measures. Although we expected a positive impact to come from people working from home, we see that closing of schools has the best results on decreasing the number of infected people. Working remotely has a negative effect as infections and hospitalisations are higher when people work from home. We will look into where and how many social contacts take place and how this results in the transmission of the virus. We will see that a decrease in physical social interaction is not enough to suppress infections by imposing these measures. The behaviour of people will change in such a way that smaller gatherings at busy locations cause almost as many infections as without the imposed measures.
Mijke van den Hurk

Chapter 6. Testing and Adaptive Testing During the COVID-19 Crisis

The scenario presented in this chapter is investigating the potential effects of different testing policies in combination with isolating households. In particular we will explore the effect of isolating the household of an infected member and giving priority in testing for healthcare and education workers. Assuming that we have more tests available than necessary for the healthcare and education workers, the effect of different strategies for the leftover tests, don’t test youth, test only elderly with leftover tests, and test everyone with leftover tests are investigated. The results show that the combination of no priority in testing + testing everyone with leftover tests + isolation of the household of an infected member is the best combination to “flatten the curve”. Furthermore, the amount of deaths, the impact on hospitals, and the effects on people in isolation are explored. This scenario has been developed on request of regional Italian authorities.
Christian Kammler, René Mellema

Chapter 7. Deployment and Effects of an App for Tracking and Tracing Contacts During the COVID-19 Crisis

The general idea of tracking and tracing apps is that they track the contacts of users so that in case a user tests positive for COVID-19, all the other users that she has been in contact with get a warning signal that they have potentially been in contact with the COVID-19 virus. This is, to quarantine potential carriers of the virus even before they show symptoms. We set up a scenario in which we test the effects the introduction of such an app has on the dynamics of infection with varying amounts of app users. Running the experiments resulted in a slightly lower peak of infections for higher app usages and the total amount of infected individuals over the course of the whole run decreased not more than 10% in any case. The app seems mainly effective in decreasing contacts and infections in public spaces (except hospitals) while increasing the contacts and infections at home.
Maarten Jensen, Fabian Lorig, Loïs Vanhée, Frank Dignum

Chapter 8. Studying the Influence of Culture on the Effective Management of the COVID-19 Crisis

In this chapter we investigate the influence of culture on the effective management of the COVID-19 crisis. In order to study culture we first describe cultures in terms of values. These values are connected to the needs of the agents, giving them a certain default priority, which differs across cultures. Then we will show how culture actually influences how people react to certain types of measurements and the effect this has on the effective management of the COVID-19 crisis.
Amineh Ghorbani, Bart de Bruin, Kurt Kreulen

Chapter 9. Economics During the COVID-19 Crisis: Consumer Economics and Basic Supply Chains

The Covid-19 pandemic has other perspectives than just the epidemiological one that impacts human lives. In this chapter, we look at the economic perspective by modelling a consumer economic system with a basic supply chain and a very basic government role to create a circular economic system. People have to work at shops or workplaces to earn money to buy food or other items. These items are sold by shops who in turn buy them from workplaces. We devise multiple scenarios to compare the effects of the pandemic, measures to lessen the epidemiological effects and additional economic effects. The results show us that we can: (1) create an useful economic model in the complex ASSOCC context, (2) that from an economic perspective repeated lockdowns are more harmful than not taking any action at all, and (3) economic measures do support economic well being of the population. While it is very clear that the real world is a lot more complex than how we have modelled it, the modelling process helps us pinpoint where next steps of policy investigation, model improvement and research could be performed.
Alexander Melchior

Chapter 10. Effects of Exit Strategies for the COVID-19 Crisis

Most focus during the Covid-19 crisis has been on which measures of governments are the most effective to curb the spread of the virus. Far less attention has been given to the best way to release the restrictions. In this chapter we discuss the various elements of the so-called exit strategies from different governments. We will group them in several types of strategies and compare the effectiveness of them. From our simulations we do not observe big differences in the outcomes from the exit strategies. Because the simulations are run on a small scale more research would be needed to see how the results could be translated to the real world. However, in practice we have seen that the effects of the different strategies in countries around the world have indeed had little effect on preventing a second wave.
René Mellema, Amineh Ghorbani

Results and Lessons Learned


Chapter 11. The Real Impact of Social Simulations During the COVID-19 Crisis

Creating simulations for a crisis is not new. However, there have been no agent based social simulations that have been used during a crisis. In this chapter we describe the impact one can have with a simulation result, but also the requirements this poses on the simulation process. Basically it requires that one can quickly and flexibly generate many variations of scenarios, explain results in terms of the decision makers and extend the scenarios with new aspects that become important in a very short time.
Frank Dignum

Chapter 12. Comparative Validation of Simulation Models for the COVID-19 Crisis

Modelling and simulation approaches are applied in a variety of scientific disciplines for analysing, planning, and optimising complex systems or phenomena. Simulation is not limited to applications related to computer science or information systems research [2] and has also become an accepted method, for example, in social sciences and medicine. But also for solving practical problems, e.g., in manufacturing, logistics, or engineering, the use of simulation is increasingly common. Due to its popularity and versatility, simulation is even referred to as a third pillar of science between theory and experiment [1].
Fabian Lorig, Maarten Jensen, Christian Kammler, Paul Davidsson, Harko Verhagen

Chapter 13. Engineering Social Simulations for Crises

Building social simulations during crises for decision-support largely expands the concerns and partly differs from building classic academic simulations: stakeholders are under high pressure and need fast and reliable answers, whereas public concerns and theoretical foundations for modelling the core aspects of the crisis regularly evolve as the crisis unfolds. Building upon the experience gathered by engineering the ASSOCC simulation, this chapter is dedicated to study how to frame the engineering activity for simulating during crises. This study includes an extended list of quality criteria of simulating in crises; an adaptation of software engineering methods to simulating during crises; and a guide and analysis for scaling up social simulation.
Loïs Vanhée

Chapter 14. Agile Social Simulations for Resilience

In previous chapters we have described the results and analysis of social simulations for crisis situations based on the experiences of the ASSOCC framework. Whereas we managed to build an implementation in a very short time, based on many years of fundamental research, such an implementation is inherently limited due to the many tasks and challenges that are to be dealt within high time pressure (e.g. keeping up with the many emerging public concerns and specific stakeholder issues with relatively unstable theoretical background while dealing with scaling up technical challenges). This chapter proposes and discusses what can be prepared for future crises, from fundamental conceptual building blocks, to decision components, and technical implementations. Building upon the experience of what we missed and had to create or deal with(out) during the crisis, this chapter is dedicated to point how, as a community, we can be ready to adaptively respond to future crises.
Maarten Jensen, Frank Dignum, Loïs Vanhée, Cezara Păstrăv, Harko Verhagen

Chapter 15. Challenges and Issues for Social Simulations for Crises

In the previous chapters we have described our experiences in simulating for the COVID-19 crisis. We also described how we envision that we can get to a simulation platform that will be more supportive for simulating a next crisis. In this chapter we will recapture a number of the challenges that need to be faced in order to make social simulations grow to their real potential in crisis situations. The challenges range from theory and conceptual models to implementation and use of the simulations. Moreover, we argue that the development of the simulation platform should be accompanied with an effort of the community to connect to established advisory boards and committees in order to integrate the social simulations in the normal set of tools that are used by crisis teams.
Frank Dignum, Maarten Jensen, Christian Kammler, Alexander Melchior, Mijke van den Hurk

Chapter 16. Conclusions

We finish the book with a chapter in which we describe what we decided not to do or include in the ASSOCC framework. Where did we stop? And why did we stop? The temptation is to keep adding more and more aspects in order to simulate more scenarios. However, at the same time the simulation would become more complex and unmanageable. We also summarise what we have learned from all the different parts of our experience. And most importantly we give a roadmap of research that would be needed to make social simulations a standard tool to be used for crisis situations.
Frank Dignum, Loïs Vanhée, Maarten Jensen, Christian Kammler, René Mellema, Fabian Lorig, Cezara Păstrăv, Mijke van den Hurk, Alexander Melchior, Amineh Ghorbani, Bart de Bruin, Kurt Kreulen, Harko Verhagen, Paul Davidsson


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