The document on Mission Entrepreneurial Entities’ comparative analysis of the United States and the United Kingdom, with implications for the global south. Mission Entrepreneurial Entities (MEEs) is a private non-government entity that is in the business of making exosystemic change by doing actual transactions valuable in themselves that also serve as pilots and proof of concept. Successful affordable housing ecosystems are populated by Mission Entrepreneurial Entities, private companies (usually non-profit housing companies) who act by converting ideas and resources into tangible properties and successful housing outcomes. Additionally, MEEs serve a critical role as change-makers in both policy and economic realms. Yet we know very little about what defines a successful MEE, and what defines the environment or initial conditions that enable MEEs to be conceived, established, nurtured, and grown to success and scale. Successful affordable housing ecosystems are populated by Mission Entrepreneurial Entities, private companies (usually non-profit housing companies) who act by converting ideas and resources into tangible properties and successful housing outcomes.