Spillover benefits and achieving sustainability of age-friendly communities.

As the age-friendly movement grows in its second decade, urgent questions of initiative sustainability have taken hold in the academic literature and among advocates implementing age-friendly changes. The creation of authentically age-inclusive environments requires not just the continuation of the initiative, but that its principles become embedded in formal and informal organizational processes, across sectors and beyond familiar networks focused on older populations. This embedding ensures the initiative's values take root permanently in a community's institutional culture. This paper argues that sustainability of age-friendly initiatives is enhanced by "spillover" effects, in which a behavioral or policy change in one environment spurs change in another environment. Evidence for such spillover and an understanding of how and when it occurs is currently limited in the context of age-friendly environments. This paper draws on the experiences of Age-Friendly Boston, which has been working towards age-friendly goals for more than five years. Based on Boston's experience, we identify, describe, and exemplify three pathways to positive spillover across environments: 1) branding positively; 2) publicizing successes; and 3) embarking on new relationships, while strengthening existing ones, in pursuit of shared goals. We also draw conclusions about what positive spillover means for the sustainability of age-friendly environments.