This issue of the Asian Economic Policy Review focuses on the interrelated issues of connectivity and economic integration in developing Asian countries. While economic integration is a widely used and understood concept, it will be useful to briefly clarify the meaning of the term "connectivity", and to explain its relevance to long-term Asian development dynamics.At the most general level, we take connectivity to refer to infrastructure, both hard and soft, that links geographical locations to facilitate the flow of goods, services, technology, finance, and people, in order to enhance mobility and networking. Traditionally, the approach to connectivity emphasized hard infrastructure (sometimes also referred to as "tangible infrastructure"), and this emphasis is reflected in the papers that follow. Examples include major highways and rail networks, and ports and airports. Broader definitions of such infrastructure include utilitiestelecommunications, power, and water supply. The information and communication technology (ICT) revolution of the past two decades is of course radically changing the analytical meaning of infrastructure and the modes of infrastructure delivery, with tele-commuting, electronic communications, and e-commerce all having profound implications for connectivity.East Asian connectivity and economic integration has proceeded rapidly for several decades, driven by four broad sets of factors. First, far-reaching unilateral trade and investment liberalization that reduces the barriers to cross-border commerce has been undertaken in virtually all economies. These reforms have been underpinned by a broadly supportive global and regional architecture, notwithstanding some backtracking during the 2008-09 global financial crisis. A second factor has been the rise of the global factory and global value chains through cross-border production networks and supply arrangements. These have been a feature of East Asian economic development since the †Correspondence: