Agent-based modeling for studying the choices of households in Switzerland

Housing plays a fundamental role in the transition towards a more sustainable society. In Switzerland, the unbalanced relationship between environmental, economic and social factors manifests itself in the current market trends of rental apartments, where data show a discrepancy between demand and supply. In fact, the impossibility for the supply to actively anticipate the change in tenants’ housing preferences often results in residential redistribution and new demand pressure. In this context, we have identified the following gaps: (i) Supply responds to the fast change in society (e.g., new family’s structure, lifestyles and comfort levels) with short-term satisfactory solutions. However, their long-term impact leads to a mismatch with the future evolving demand. In fact, the lack of understanding of system dynamics often causes actors to react to the system’s outputs, and to neglect the structure responsible for a specific behavior. Understanding the system structure is key to recognizing patterns, and to propose sustainable solutions accordingly. Therefore, studying the way tenants make decisions concerning their residential mobility is fundamental to design scenarios based on the system’s dynamics and to provide support for policy-makers, practitioners and households. (ii) Research on residential mobility and location choices is often fragmented in disciplinary silos, prioritizing the role played by housing characteristics (e.g., size, location, view) as determinants of decisions for the selection of a new dwelling. However, going beyond disciplinary fragmentation, housing function can be considered as the most crucial determinant of the system’s dynamics. Considering the lack of interdisciplinary and systemic approaches to housing and the related difficulty of the sector to predict and adapt to changing needs while providing sustainable solutions, the research aims to develop a model representing the way households take decisions concerning their residential situation. This allows to evaluate and propose measures supporting the transition towards housing sustainability in Switzerland. To fulfill this goal, a conceptual framework is developed, representing the factors influencing tenants’ decisions to move and where to move. From the framework, decision-making rules are derived, which allow for developing an Agent-Based Model (ABM) simulating tenants’ relocation decisions. To run the model, quantitative data on buildings and households are gathered from the database of our three partners: the cooperatives SCHL and ABZ and the insurer and asset manager Swiss Mobiliar. With the support of the qualitative findings of two Group Discussions with our partners’ tenants in Vaud and Zurich, we will conduct a large survey. Its results will feed into the model allowing, together with the behavioral rules, for simulating the interplay between households and dwellings. The Agent-Based Model of households’ residential decisions will feed an interdisciplinary collaborative model including social, economic and environmental factors as well as demand and supply requirements. The resulting baseline scenario will be used for the simulation of policy changes and the identification of new paths for the transition towards a more sustainable housing. These paths will be developed and assessed with a transdisciplinary approach involving our three partners and the Federal Housing Office, with the aim to propose a set of agreed policy recommendations for property owners as well as cantonal and federal authorities.