How Unique Is the Current Era?

This month’s issue offers a brief quantitative economic history of the world economy, including a discussion of the sources of growth and decline during the past two millennia. What can they tell us about how unique our current era is or may become in terms of economic transformation? There are some common threads explaining the reasons for economic advances: population growth, investment and productivity, and key innovations in technology and institutions, including government. But there are also large differences with regard to the past, an important difference being the greater interconnectivity of the global economy.