Phills, Deiglmeier, and Miller’s 2008 study (“Rediscovering Social Innovation,” Stanford Social Innovation Review) redefined the concept of social innovation by defining it as an interdisciplinary ecosystem.
This approach breaks with the idea that innovation can be attributed to a single organization or actor. Instead, it argues that social change is the result of multisectoral collaborations: the state, civil society, the business community, and academia all work together to create social value.

The ecosystem approach is about interdependence and coordination: each actor contributes its own resources and knowledge to the common goal, while also learning from the process.
Innovation is thus not a single solution, but a continuous dynamic of collaboration that shapes new institutional patterns and social norms.

One important contribution of the Phills–Deiglmeier–Miller concept is that it interprets social innovation as a systemic process, which is only viable if there is a transition, knowledge sharing and partnership between the actors.
This approach had a great influence on subsequent innovation policies at the European and UN levels, which are now built around the concepts of “intersectoral governance” and “co-creation”.