Rana and Allen focus on a relatively neglected research area: how business systems theory (BST) can help explain entrepreneurship. The authors employ this theory to understand: why a particular business model is developed; why entrepreneurs tend to make a particular type of decision, in a particular way, for a particular context; why firms or new ventures structures, strategies, and growth trajectory follow a particular path dependency in a particular institutional context; while complementarity and/or lack of complementarity present different types of opportunities, challenges, and growth patterns for new ventures or new industries in a society. The authors illustrate how BST can help to explain entrepreneurial decision-making, motivation, venture, and industry creation, social entrepreneurship, diaspora entrepreneurship, and, above all, institutional entrepreneurship in national and comparative institutional contexts.