Signaling climate resilience to municipal bond markets: does membership in adaptation-focused voluntary clubs affect bond rating?

This paper examines whether US cities’ membership in voluntary climate clubs improves the municipal bond ratings issued by S&P, Moody’s, and Fitch. We suggest that only clubs focused on climate adaptation could help cities signal their resilience to climate risks and their ability to service their municipal bonds. Yet, club membership is only a signal of intent. By itself, it does not offer concrete evidence that cities have adopted adaptation policies or enhanced their resilience to climate risks. We examine three climate clubs: ICLEI, whose membership obligations cover climate and other environmental issues; C40, whose scope covers both climate mitigation and adaptation; and 100 Resilient Cities (100RC), which focuses on adaptation only. Employing a two-way fixed effects model for a panel of 80 US cities from 1995 to 2018, we find that 100RC membership leads to a small improvement in bond ratings. This has important policy implications: Assurances about implementing adaptation policy, as opposed to evidence about how adaptation reduces climate risks, could have spillover effects on municipal finance. In such cases, climate adaptation could have tangible implications for city-level finances.