As the effects of climate change intensify, the need for efficient and equitable climate adaptation policies is becoming more urgent. This is especially true for U.S. coastal counties impacted by climate-induced sea-level rise and the socio-economically vulnerable areas within them that are often characterized by higher flood risks.
Conventional benefit-cost analyses used to allocate adaptation resources in coastal areas have often resulted in distributional inequities. In a study(Link is external) examining flooding adaptation measures in New York City (NYC), researchers at Princeton University and the Environmental Defense Fund show how a new type of benefit-cost analysis can better account for the value of flood mitigation benefits to low-income households.
The study focuses on two adaptation measures: property buyouts and retrofitting. Property buyouts are when governments purchase properties from residents in high flood-risk areas, while retrofitting involves elevating and wetproofing buildings. For each adaptation measure for each building, the researchers calculated benefit cost ratios (BCRs). The researchers calculated adaptation costs using data from the NYC Department of City Planning and the Federal Insurance and Mitigation Administration. The benefits of each measure was quantified by calculating the value of expected avoided damages over a 50-year time horizon.
In an alternative model, the researchers recalculated benefit cost ratios with “equity-weighted” benefits that would operationalize the assumption that a dollar saved from avoided damages would have a greater effect on a low-income household’s well-being than a high-income household. In a benefit-cost analysis, these weights effectively place more value on the benefits of buyouts and home elevations in disadvantaged communities.