Why do countries differ so greatly in their patterns of political cleavage and coalition? Extending some basic findings of economic theories of international trade, Ronald Rogowski suggests a startling new answer. Testing his hypothesis chiefly against the evidence of the last century and a half, but extending it also to the ancient world and the sixteenth century, he finds a surprising degree of confirmation and some intriguing exceptions.

Why do countries differ so greatly in their patterns of political cleavage and coalition? Extending some basic findings of economic theories of international trade, Ronald Rogowski suggests a startling new answer. Testing his hypothesis chiefly against the evidence of the last century and a half, but extending it also to the ancient world and the sixteenth century, he finds a surprising degree of confirmation and some intriguing exceptions.