Nikolaos Zahariadis has written an interesting and ambitious book that extends to other countries and later stages of the policy process John Kingdon's classic insight into agenda setting—that policies are the result of streams of problems, solutions, and politics, coupled by policy entrepreneurs when windows of opportunity open.

According to Zahariadis, extending Kingdon's multiple-streams framework demands a clear understanding of ambiguity and of how choices are made when there are “many ways of thinking about the same circumstances or phenomenon” (pp. 2–3). Building upon Michael Cohen et al. (“A Garbage Can Model of Organizational Choice,” Administrative Sciences Quarterly 17 [no. 1, 1972]: 1–25), the source that inspired Kingdon's original work, Zahariadis notes that multiple streams are the structural factors and cognitive processes through which meaning is created from ambiguity. What is needed is a better understanding of how ambiguity and multiple streams come together to create meaning in different national settings and stages of the policy process. Rather than modifying Kingdon, Zahariadis gives greater specification to the multiple-streams framework in three areas and then applies these new specifications to a set of case studies.

First, while Kingdon argues that policy entrepreneurs focus attention by taking advantage of opportunities in the politics and problem streams, Zahariadis provides a more nuanced analysis of the role that symbolic politics plays in a policy entrepreneur's arsenal. Under conditions of widespread ambiguity, policymakers and the public are particularly vulnerable to political manipulation through symbolic politics.

Second, while multiple-streams theory argues that solutions germinate from within a “primeval soup,” Zahariadis goes further to show how the period of gestation and adoption are dependent upon the degree to which the policy community is integrated. In less integrated networks—larger in size, more competitive, with lower administrative capacity, and more restricted access—new solutions are quickly embraced but then follow a long and slow period of “softening” in which they become marginal extensions of existing policies.

Finally, Zahariadis demonstrates that under conditions of ambiguity, people are loss averse and are likely to engage in risk-seeking behavior to recoup losses. Thus, if the policy solution is a large deviation from the status quo, entrepreneurs are more likely to be successful if the solution is presented as a loss. He describes several strategies to achieve this goal, including framing, using symbols, and engaging in “salami tactics.” In a “salami tactic,” a policy entrepreneur divides (slices) the process into distinct stages, presents them sequentially to policymakers, and thereby succeeds in promoting agreement incrementally.

Zahariadis threads his specifications of Kingdon's model through a set of case studies in four different European parliamentary systems (France, Germany, Britain, and Greece) and a computer simulation of a parliamentary system.

Three chapters examine privatization experiences in Europe, one of which compares the privatization of the telecommunications authority in France and Britain. Zahariadis argues that the coupling of the three streams explains the successful sale of British Telecom, while the inability to link all three streams accounts for the failure to privatize France Telecom. A second (coauthored with Christopher Allen) compares the postwar privatization experiences in Germany and Britain to demonstrate how the level of integration among policy networks influences the trajectory of ideas in the policy stream. In a third chapter, Zahariadis examines the timing of British Rail's privatization, arguing that the success of British Rail's privatization in 1993 was a function of successful coupling by Conservative policy entrepreneurs. Following the three chapters on privatization, which rely on secondary sources, Zahariadis turns to his own research on Greece's foreign policy toward the former Yugoslav Republic of Macedonia during the 1990s.

This is the strongest chapter in the book, and it effectively illustrates the usefulness of multiple streams and the importance of Zahariadis's specifications. As a bonus, we learn a good deal about a very interesting case. In the face of significant European and American opposition, Greece vehemently opposed recognition of the fledgling state from 1991 to 1995. The author draws upon his own extensive research and data (including 31 interviews with Greek policymakers) to demonstrate how policy entrepreneurs' use of Greek nationalism succeeded in framing the issue of recognition as a direct challenge to Greek identity. He goes on to demonstrate how President Andreas Papandreou in 1995 succeeded in changing Greece's foreign policy using salami tactics, that is, by manipulating officials to do something they would not otherwise agree to by slicing the process into small steps and using the steps to deceive policymakers about the true objective.

In a final empirical chapter, Zahariadis reconsiders Cohen et al.'s (1972) Garbage Can Model of organizational choice by developing a Monte Carlo computer simulation of a parliamentary system to assess the performance of multiple streams.

Overall, Ambiguity and Choice in Public Policy is interesting and ambitious. The specifications of Kingdon's model are intriguing, and I enjoyed reading examples of multiple streams applied to national systems that differ institutionally from America. At the same time, the book suffers from several weaknesses. Zahariadis neglects to make a strong case for why one should want to apply Kingdon's model to other settings. What does one gain from relying on multiple streams over other approaches that explain policies in other countries? Particularly striking is the lack of attention to scholarship in comparative political economy by Peter Hall, Paul Pierson, David Soskice, and many others, which goes to great lengths to understand how institutions constrain the selection of policymakers' choices. Indeed, the role of institutions is noticeably absent or underdeveloped in the explanation of policy outcomes. This is surprising since a stated purpose of the book is to extend Kingdon's model to other institutional settings.

A final concern is the book's structure, selection of cases, and mix of methodologies. Chapters on privatization, Greece's foreign policy, and a computer simulation of multiple streams are an odd combination. The chapters differ significantly in methodology and scope. Scholars of privatization, in particular, will scratch their heads at the comparisons and some of the details (or lack thereof). At the same time, the mix of cases and methodologies underscores the fact that this is very much a volume designed to illustrate the efficacy of Kingdon's theory. And while specialists in privatization policy or Greece's foreign policy might take issue with some of Zahariadis's accounts, the book nevertheless succeeds in its primary goal of giving us additional theoretical tools to apply multiple streams to other countries and stages of the policy process.