Richard Ned Lebow. (2014). Constructing Cause in International Relations . Cornell University Press, Ithaca, NY, 208 pp., $90.00 hardcover (ISBN 978-1-107-67288-8). The primary aim of Constructing Cause in International Relations is to introduce the concept of inefficient cause into the crowded lexicon of causal talk in International Relations research. Lebow argues that many events in world politics—the First World War or the rise of the territorial state—are singular events, meaning they are “causal but non-repetitive” (152). These “one-offs”—uncommon effects—cannot be explained using traditional accounts of causation that emphasize statistical associations with common causes; instead, to search for causes of these events, one must trace the web of uncommon causes that produced them, focusing on what is special about the event rather than what is generic. The central argument of Constructing Cause comes after a few chapters that advance a theory of the origins of causal pluralism, in which Lebow adopts the anti-realist position that causes are constructed by researchers, rather than being features of the natural or social world. This kind of pluralism allows researchers to construct new, useful concepts of causation. In this spirit, Lebow adds inefficient causation into the already crowded field of causal-talk jargon to capture intuitions about how to explain singular events. The term inefficient causation , on my reading, is perhaps better called inefficient causal analysis or inefficient causal explanations , because it is a strategy or “multi-step process” for identifying causal factors rather than a kind of cause per se (65). The first step is to select some event in world politics, such as the formation … ericgryn{at}gwu.edu