While entrepreneurial ecosystems are on the edge of policy makers’ agenda, the concept still suffers from a number of shortcomings regarding their conceptualization, measures and level of analysis. This book provides readers with a critical review of the received literature on entrepreneurial ecosystems, a theoretical framework to contribute to make it explicit what is cause and what is effect, and in-depth analyses of several practical cases. The book ends with a discussion of the policy and research implications of findings and identifies avenues for future research.