Daily insights for city builders, delivered every morning at 6 AM ET. I’m Brandon Donnelly — a Toronto-based real estate developer and founder of Globizen. I’ve been writing here since 2013.

Tag: climate risk

  • Redfin experiment shows how home buyers react to flood-risk data

    This is a fascinating little experiment:

    From Oct. 12, 2020 to Jan. 3, 2021, Redfin ran an experiment on 17.5 million of its users across the US. As prospective homebuyers entered the site, Redfin assigned them randomly to either a group that was shown flood-risk information on each property or a group that was not.

    The flood-risk scores came from First Street Foundation, a climate and technology nonprofit that works to make climate hazards more transparent to the public. In June 2020, First Street published the first public maps that revealed flood risk for every home and property in the contiguous US. 

    First Street scores properties on a scale of 1 to 10 based on the likelihood that they will flood in the next 30 years (which is assumed to be a typical mortgage term). A score of 1 means the property has “minimal” risk and a score between 9-10 is considered “extreme” risk.

    So what happens once you start showing people flood-risk information? They, not surprisingly, start systematically looking for safer properties. After one week of users being exposed to this new information, prospective buyers who were previously looking at “extreme” homes started looking at homes that were about 7% safer.

    After 9 weeks, these same “extreme” home buyers were looking at properties that were about 25% less risky. And for some buyers, in particular those working with a Redfin agent or partner, their flood-risk tolerance dropped by over 50%. (Embedded in this data might be a sales pitch for working with a knowledgeable Redfin agent or partner).

    Also interesting is the fact that below “severe” flood risk (a score between 7-8), there was very little change in behavior. “Major” flood risk, it would seem, isn’t all that concerning to most buyers. It needs to be “severe”. Nevertheless, it is noteworthy that people will in fact make behavioral changes when presented with clear climate-risk data.

  • Floodplain homes in the US are overvalued by a total of $34 billion

    This recent paper by Miyuki Hino (University of North Carolina) and Marshall Burke (Stanford) makes the case that US homes situated within floodplains are currently overvalued by a total of $34 billion. And that’s because the associated risks are not being properly accounted for in the value of these homes.

    The problem, it would seem, comes down to information. Because the discount for flood risk was found to be higher (1) for commercial buyers (presumably because they’re more sophisticated and/or have better access to information) and (2) in states where sellers must disclose flood risk (Louisiana is probably the most stringent about this).

    This feels a bit like one of those realtor commercials that tries to scare you into using one. But it does appear to demonstrate just how opaque the market can be and how information asymmetries potentially distort asset prices. Perhaps most importantly, I wonder when climate risk will get fully valued.