International Journal of Economics, Commerce and Management United Kingdom Vol. VII, Issue 2, February 2019 Licensed under Creative Common Page 198 http://ijecm.co.uk/ ISSN 2348 0386 SOCIAL ENTREPRENEURSHIP: SUSTAINABILITY AND SOCIAL IMPACT BY NOT-FOR-PROFITS: THEORY AND EVIDENCE Japheth M. Muli School of Business and Economics, Machakos University, Kenya japhethmuli@yahoo.co.uk Robert Arasa School of Business and Economics, Machakos University, Kenya rarasa4@gmail.com Abstract Social Entrepreneurship (SE) is; identification of a social problem and a solution for the problem; the evaluation of the social impact, the business model and the sustainability of the venture. This paper is a review of scholarly work on SE and how it creates sustainability of the social mission of not-for-profit organizations. Relevant previous studies have been reviewed and interrogated. The review of scholarly work reveals that Faith Based organizations have taken lead in SE and have obtained sustainability from these efforts. Other private and corporate entities have indulged and excelled in SE, for instance the Grameen bank. Governments e.g. UK, USA, Kenya etc. in their policies have given cognizance to SE for not-for-profits. The findings of this study gives the overall picture that; there is more assurance in the continuity of the work of not-for-profit organizations through the sustainability created by investing in social enterprises. Discussed and reviewed id the theoretical backing of SE being; the Framing theory of social entrepreneurship, theory of resource base, behavioral theory of the firm, the theory of sustainability, change theory, and the capability-based theory. There is opportunity for further research to develop knowledge based numerical evidence on the financial sustainability brought by SE. Keywords: Social entrepreneurship, not for profits, sustainability, social impact