@techreport{oai:ir.ide.go.jp:00037876, author = {Nabeshima, Kaoru and Tanaka, Kiyoyasu}, month = {Apr}, note = {application/pdf, IDP000297_001, The growing importance of innovation in economic growth has encouraged the development of innovation capabilities in East Asia, within which China, Japan, and Korea are most important in terms of technological capabilities. Using U.S. patent data, we examine how knowledge networks have developed among these countries. We find that Japan's technological specialization saw gradual changes, but those of Korea and China changed rapidly since 1970s. By the year 2009, technology specialization has become similar across three countries in the sense that the common fields of prominent technology are electronics and semiconductors. Patent citations suggest that technology flows were largest in the electronics technology, pointing to the deepening of innovation networks in these countries. Together with our prior work, the Japanese and U.S. data produce similar conclusions about innovation networks.}, title = {Innovation networks in China, Japan, and Korea : further evidence from U.S. patent data}, year = {2011} }