The volume and quality of the scholarship generated of late on the question of the “varieties of capitalism” has been truly outstanding. We now know far more than we ever did about the internal workings of particular national economies, and about the determinants of what Angus Maddison once termed the “proximate” causes of their competitive strengths and weaknesses. That knowledge has come in part from the work of a talented set of comparative political scientists and industrial sociologists, many of whom participate in this collection. It has also come from the work of a set of economists and economic historians with sufficient professional courage and intellectual integrity to operate at (or even beyond) the edge of their notoriously narrow and institutionally blind discipline. But because that knowledge has come from so many sources, and because so much of it has entered the public domain in the form of discrete case studies or collections of relatively disconnected essays, what the subfield now needs, more than anything else, is the consolidation of a set of organizing frameworks and governing concepts designed to go beyond proximate causes to a fuller understanding of the dynamics of competitive advantage. This is why Peter Hall and David Soskice's much-heralded collection of essays, Varieties of Capitalism, is so important a milestone in the development of the subdiscipline of comparative political economy. At long last it gives us what Pepper D. Culpepper calls here an “analytical tool kit” (p. 303): a collection of essays built around the powerful conceptual devices of “comparative institutional advantage” and “institutional complementarities”—concepts deployed to explain “how the institutions structuring the political economy confer comparative advantages on a nation, especially in the sphere of innovation” (p. v).