Delegation and Agency in International Organizations. Edited by Darren G. Hawkins, David A. Lake, Daniel L. Nielson, Michael J. Tierney Cambridge: Cambridge University Press, 2006. 424 pp., $80.00 cloth (ISBN: 0-521-86209-4), $34.99 paper (ISBN: 0-521-68046-8). Darren Hawkins, David Lake, Daniel Nielson, and Michael Tierney open Delegation and Agency in International Organizations by sketching two metaphors that capture contradictory popular understandings of international organizations (IOs). For some, contemporary international organizations are “institutional Frankensteins terrorizing the global countryside” (p. 4). For others, they are little more than willing tools of their creators. This distinction frames the book, which is divided into two main sections. The first examines “when and why … states delegate to an IO and what sets of rules govern that interaction” (p. 5). The second focuses on the sources of IO behavior after they are established as well as the ability of states to anticipate potential problems and maintain control. To gain leverage over these questions, Hawkins, Lake, Nielson, Tierney and their contributors turn to principal-agent theory, arguing that it is equally relevant for international relations as it is for domestic politics. Given that principal-agent theory has been less prominent in international relations than in the study of US politics, the volume's most immediate contribution may lie in the Introduction's comprehensive and clear elaboration of the principal-agent framework. Hawkins, Lake, Nielson, and Tierney explain that “to be a principal, an actor must be able to both grant authority and rescind it” (p. 7). Furthermore, delegation involves “a conditional grant of authority from a principal to an agent ” (p. 7, italics in the original). The editors define “agency slack” (unwanted independent action by an agent) as a potential problem with any delegation. They distinguish two forms of slack: shirking (in which an agent minimizes effort) and slippage (in …