A risk model to describe the behaviours of actors in the houses falling into the sea problem

• Managing sea level rise for existing assets has focused on geophysical attributes.
• By contrast, managing risks to existing assets is largely a socio-economic problem.
• The traditional approach does not describe the observed behaviour of the key actors.
• We propose a new model, based on the allocation and distribution of risk.
• This model better describes the observed behaviours of the key participants.

The long-term solution to managing the impacts of sea-level rise is through the development and application of planning provisions and public policy, especially with regards to new developments in the coastal zone. By contrast, imposing new planning provisions, such as enforced retreat strategies, on legacy or existing private assets that are exposed to erosion and sea-level rise will impact on private property rights. In many cases this will incentivise rights-holders to pursue alternative recourse pathways. It is argued here that the behaviour of the key actors in this legacy assets problem are not well described in the models commonly proposed in the literature, and a new risk-based model framework is proposed that better explains the observed behaviours.