Working Paper

Flood Risk Exposures and Mortgage-Backed Security Asset Performance and Risk Sharing

Abstract: The distribution of risks for residential real estate, including flood risk, depends largely on how these risks are allocated across individual mortgages and within mortgage-backed securities (MBS). This paper is the first to document how flood risks relate not only to individual mortgage performance and underwriting, but also how flood risks correlate to MBS performance and structure. Across residential mortgages we find that defaults are concentrated among the most flood-prone properties and this risk is somewhat offset by larger down payments and slightly higher mortgage rates. Even when mortgages are combined into MBS’s, we show that average mortgage default within MBS’s increases with average flood risk and that higher flood risk is primarily offset by increased credit protection or subordination; a one unit increase in flood risk is associated with a 2.6 percent increase in subordination. Ultimately, our analysis suggests that flood risk is reflected in mortgage-level performance and pricing and is partially, but not fully, accounted for in MBS deal-level performance and structure.

Keywords: climate risk; flooding; mortgage-backed securities; structured finance; bond markets;

JEL Classification: Q54; R30; D89; G12;

https://doi.org/10.18651/RWP2024-05

Bibliographic Information

Provider: Federal Reserve Bank of Kansas City

Part of Series: Research Working Paper

Publication Date: 2024-05-21

Number: RWP 24-05