Is on the Claremont Review web site (it did not make the dead-tree publication).

How is it that in the 19th century, England came to have dominion over so many lands and so many peoples? Though he uses modern quantitative methods, economic historian Gregory Clark reverts to a Victorian answer: the superiority of what Winston Churchill was fond of calling “our island race.”

…His quantitative techniques for demonstrating such phenomena as the innumeracy of pre-industrial humanity and the evolution of the speed of information flows are clever. However, the contest between institutional accounts of economic performance and Clark’s cultural explanation is probably best resolved through a synthesis. Clark’s attempt at a winner-take-all for cultural Darwinism falls short.