Are entrepreneurs essentially the same everywhere? Are the processes of entrepreneurship similar? Or are they shaped by their environments? If so, how? We know a lot about national differences in management practices, corporate governance, and even innovation systems, but we know surprisingly little about national differences in entrepreneurship. Comparative Entrepreneurship compares processes of entrepreneurship in the UK and Japan, countries associated with liberal market economies and coordinated market economies respectively. Focusing on high tech manufacturing it identifies basic similarities and key differences. Similarities are found in approaches to opportunity and business creation, which are strikingly different from recent policy emphases in the UK and Japan, inspired by Silicon Valley (hence the entrepreneurs live in 'the shadow of Silicon Valley'). Differences - in the backgrounds of entrepreneurs, founding teams, attitudes to growth and risk, innovation, competitive advantages, HRM emphases, and inter-firm collaborations - are summed up by the concepts of 'project entrepreneurship' and 'lifework entrepreneurship.' These are closely related to the respective environments, especially the nature of markets in both countries. They also embody different time orientations, with implications for financing and governance. This study brings insights from entrepreneurship to comparative institutions and varieties of capitalism, and vice versa, and draws on two surveys and 25 case interviews in both the UK and Japan. It concludes with a discussion of dilemmas for entrepreneurship policy in the UK, Japan, and other countries.