This paper shows how and why the Solow growth accounting framework is useful for linking entrepreneurship capital to economic growth. The knowledge filter impedes the spillover of knowledge for commercialization, thereby weakening the impact of knowledge investments on economic growth. By serving as a conduit for knowledge spillovers, entrepreneurship is the missing link between investments in new knowledge and economic growth. Entrepreneurship is an important mechanism permeating the knowledge filter to facilitate the spillover of knowledge and ultimately generate economic growth. The emergence of entrepreneurship policy to promote economic growth is interpreted as an attempt to promote entrepreneurship capital, or the capacity of an economy to generate the start-up and growth of new firms.