His research led him to conclude that culture and institutions influence the performance of both individual entrepreneurs and large multinational corporations. He developed a leader-follower theory of culture in which leaders set cultural norms which condition the way in which entrepreneurs and managers take decisions. Historical research is the natural way to test such a theory, and his recent work has therefore focused on the application of institutional theory to business history and economic history. This led him to undertake a major study of Victorian British entrepreneurship - the building of the railway system through private enterprise - which is the subject of one of his most recent books.