David Lewis's book begins with the all-too familiar story of Michael Brown's leadership of the Federal Emergency Management Agency (FEMA) during and after Hurricane Katrina's impact on the Gulf Coast. This story aptly describes the main points of the book: that presidents use appointments to respond to specific political and policy dilemmas they face while administering their duties, and that presidential appointments have important implications for the performance of government agencies.

Why do some agencies have many appointees and others few? How do political appointments influence management? Lewis asks and endeavors to answer these key questions in order to address what others have noted as defining characteristics of presidential appointments in the modern era: that politicization is increasing and is carried out mainly by Republican or conservative presidents, and that it damages the competence of agencies. His answers to these questions overturn our conventional wisdom about the president's motives and actions, helping integrate the study of the presidency with streams of research central to the study of both political and bureaucratic processes.

Lewis offers a description of politicization over time in the context of the evolution of modern personnel systems, a formal theory of presidential incentives to politicize, a quantitative investigation of patterns of politicization over time, statistical models testing his theory about why presidents politicize and the impact of that politicization on agency performance, and an extended case study of FEMA. This array of approaches is the book's hallmark: Lewis binds together theory, cases, data, and tests in a synthetic whole that shows the mechanisms that underpin presidential appointments, as well as the mechanisms through which presidential appointments are translated into policy. He offers a first-rate example of how to move the “empirical implications of theoretical models” (EITM) in political science beyond Congress. His contribution here certainly enriches the study of the presidency and bureaucratic politics, but the book also speaks to the interests of theorists who want to understand incentives in political institutions, public administration scholars who want to understand performance, and those interested in the evolution of the modern administrative state (and the appointees and civil servants who populate it).

There are distinct highlights in this book. Chapter 2 on the evolution of the modern personnel system is expert, comprehensive, and descriptive, but also offers unique views drawn from numerous interviews. It clearly and accurately describes the twin problems in appointments: filling positions with persons and finding positions for persons. This “double-matching” problem is often seen in labor economics, but the problem is real for presidents, and we rarely describe the institutional structure of how presidents solve this problem as the political process it is shown to be here.

The formal model in Chapter 3 builds on a small set of critical assumptions. Of course, assumptions are always open to question (and to a degree, Lewis questions them), but few students of the presidency will find these assumptions worrisome. Students of bureaucracy might, though. For example, organization theorists have long held that the structure of organizations is as important as who staffs them. Likewise, others might question the meaning of “technical competence” absent some set of political preferences or an ideology. Small concerns aside, the real contribution of the chapter is to offer a formal logic for politicization when, as many will probably admit, conventional wisdom is largely driven by administration-specific concerns.

The fourth and fifth chapters are the real core of the book because they describe the changing patterns of politicization across time, type of agency, and type of appointment, as well as between eras. This is a massive data exercise and proves revelatory about what exactly has been happening for the last 50 years in terms of increasing politicization. We now know that politicization increased over time, but that the recent era has been more “ebb and flow.” The real changes have been at the agency level—not across the entire federal government—and it is this discovery that justifies the statistical models that follow.

The first set of statistical models show fairly strong evidence for the propositions that Lewis derives. The second set show that there is a performance loss to politicization. The evidence is assembled with great care and helps complete the connection between theory and models called for in the EITM movement (but often lacking in the study of the presidency and bureaucracies). The evidence is compelling, though, partly due to the presence of the FEMA case study. This case offers insights into when and where politicization can improve performance, how design affects politicization, and the degree to which agencies attract low-quality appointees. Lewis recounts the changing fortunes of the agency, with increasing numbers of appointees in the George H. W. Bush administration, James Lee Witt's professionalization revolution during the Clinton administration, and the “true politicization” of FEMA after its absorption into the Department of Homeland Security. The impacts are seen most clearly in the events associated with Hurricane Katrina. The end result is that the positive impact of political leadership during the Clinton administration was damaged with politicization during the recent Bush administration.

In the end, presidents use appointments for both managerial and political purposes, and the book provides a measure of evidence for those motivations and their consequences for bureaucratic performance. In his conclusion, Lewis offers concrete and important lessons for understanding the president and his or her power of appointment in the broader context of American democratization. There are certainly policy implications here, ranging from limits on the number of appointees to externally enforced restrictions on appointees' qualifications, but those are fairly minor in comparison to the bigger picture of uncovering and documenting the mechanisms of governance that define the president's role in America.

This is certainly the best book on appointments so far, and one that will come to define how we write books on the presidency that attempt to meld theory and evidence. Readers may have concerns about the modeling, the measure of performance, or the gradually changing meaning of “professional” (as opposed to “political”), and these concerns will drive the next generation of research on presidents, appointees, and the bureaucracies they attempt to control. But The Politics of Presidential Appointments will provide the starting point, and rightfully so.