The rapid and formative rise in research on social innovation and entrepreneurship means that theoretical frameworks are still being created, while traditional notions of economic efficiency and social welfare are tested. The field is progressing fastest in the measurement and measuring of social entrepreneurial effectiveness. Social innovators, who draw from philanthropy, as well as capital markets, for financial resources, have adopted the lean start up as a paradigm for their organization logics. This collection showcases the myriad emerging philosophical, methodological, and theoretical approaches, many of which are led by practitioners. It is organized into five sections. The first section reports on theoretical approaches to researching sustainable entrepreneurship that are less familiar. The second section reports on research focusing on the entrepreneurial responses to problems of climate change. The third and fourth sections report on research investigating social entrepreneurial processes, and how opportunities are formed and exploited. The fifth section reports on the ethical dimensions of social innovation. Researchers, scholars, educators and policymakers will find this book a useful reference, with novel ideas for future research and discourse. Contributors include: S.G.S. Abdelgawad, P. Bruner, R. Cortina-Cruz, M. Cortina-Mercado, R. Defiebre-Muller, P.F. Diochon, A.G. Earle, H.D. Fountaine, R. Harrison, R.T. Herko, K. Joensuu, K. Kaesehage, L. Katz, M. Leyshon, S. Lopez-Palau, M. Makela, S.D. Ocampo, T. Onkila, M. Pasquini, B. Rivera-Cruz, M.A. Tietz, Y.W. Turell, D. van der Horst, F.I. Viola, D. Windsor, M. Zhang