It is widely believed that globalization has proceeded to the point where international economic linkages are as strong as those within nations. Struck by research suggesting that this perception is dramatically mistaken, John Helliwell spent three years assessing the evidence. The results are reported in this book, the latest in Brookings' Integrating National Economies series. It provides the most systematic measurements yet available of the relative importance of global and national economic ties.

The original finding, based on a gravity model of trade flows, was that 1988 trade...