Congress's use of expertise represents a paradox. The legislative branch spends hundreds of millions of dollars every year acquiring policy-relevant knowledge. Standing committees hire scores of experts and regularly ask outside specialists to testify. Entire research agencies have been created to generate expert assessments on complex issues. Making specialized knowledge available to legislators is justified as a necessary expense if they are to produce laws that will do a good job in fulfilling the nation's goals.

The textbook account of Congress, however, holds that these prodigious efforts to acquire policy knowledge are mere window dressing. Policy expertise does not significantly shape the laws Congress passes. Members of the House and the Senate do not require specialized knowledge to respond to simple demands from their constituents for federal resources. Why then would Congress pay the high cost of gaining access to expertise if that knowledge is largely ignored? Kevin Esterling's new book moves us closer to resolving this paradox by making a convincing argument that Congress periodically uses specialized expertise to identify and adopt socially efficient policies.

Esterling develops his theory from the premise that citizens and other political actors are instrumentally rational. Their rationality is “bounded” because their ability to gather and evaluate information about the means to fulfill their wants is limited. He argues that citizens recognize their ignorance and give legislators discretion to draw on expertise to craft public policies that serve a wide range of interests. Public debate among interest groups in congressional hearings provides legislators a means to learn whether the promised benefits from reforms will be realized.

The principal obstacle to devising good policy, according to Esterling, is not from the clash of interests but results from the lack of convincing evidence about a policy's likely outcomes. A persuasive argument in favor of a policy requires that proponents make credible causal claims: If we do x then y benefits will occur. The author argues that members of Congress often discover from public hearings that uncertainty about proposed reforms is unacceptably high. Even when empirical evidence is available, the findings are frequently too ambiguous to justify action due to methodological or analytical differences in past research.

The first half of this book carefully lays out this theoretical argument. Separate chapters address the roles that citizens, pressure groups, and Congress play. In the second half, an empirical investigation gathers data on the positions that interest groups took in public hearings on emissions trading, school vouchers, and health maintenance organizations (HMOs).

Emissions trading, for example, was an innovative policy proposed to reduce acid rain at a far lower cost than traditional command-and-control regulations. The challenge was to convince Congress to endorse a new approach to environmental protection. Esterling maintains that his theory explains why proponents were successful: Strong empirical support from several studies by the Environmental Protection Agency minimized expectations about this policy's uncertainty and generated little ambiguity. He measured the balance of interest group support and opposition by coding the content of their testimony in congressional hearings. Uncertainty over this reform was low because many groups endorsed the belief that emissions trading would work and no pressure group disagreed.

Esterling's research offers an important and persuasive contribution to the enduring debate over the role of expertise in legislative policymaking. His analysis defends strong propositions within well-defined analytic boundaries. He agrees that the conventional wisdom may be correct that specialized knowledge has little impact in many of the policy decisions Congress makes. He focuses on those rare cases in which policy expertise is well developed and offers pressure groups a rationale for backing policies that serve both their welfare and the interests of most citizens.

Because Esterling seeks to explain a narrow portion of a complex policymaking process, questions immediately arise about what lies just beyond the analytic boundaries of his study. How rare, for example, are his research-driven policies? His theory does not address this question and his empirical investigation examines only two cases. He restricts his focus to social science research. Since the social sciences are seen as less mature and credible than the natural sciences, would his expertise-driven process occur more often or unfold more expeditiously when pressured by research from the natural sciences?

Some explanatory factors that others have identified fall within the scope of Esterling's analysis and, if addressed, could have improved the final product. The agenda-setting literature (e.g., see John Kingdon's Agendas, Alternatives, and Public Policy, 2d ed., 1995) agrees with Esterling on the importance of identifying credible policy solutions, but finding answers may not be sufficient to produce new policy. Decision makers must also be persuaded that the problem is severe enough to require action. Problem recognition receives little or no attention in Esterling's theory, even though experts' claims about the scope of emerging problems may be decisive in attracting congressional attention. The key role he attributes to congressional committees in identifying effective policies naturally calls to mind Keith Krehbiel's argument in Information and Legislative Organization (1992). Krehbiel maintained that the ideological heterogeneity of standing committees determines which policy solutions are politically feasible and, by implication, the type of research that committee members would seriously consider. Stepping back, Esterling is concerned with improvements in the quality of technical knowledge that is available to interest groups and congressional committees on particular policies. Certainly his work would have benefited from engaging Paul Sabatier's impressive work (e.g., see Policy Change and Learning, 1993) on this very topic.

One final issue is Esterling's decision to ground his analysis in theories of bounded rationality. This choice is puzzling because the concepts he uses are more consistent with a standard rational choice account. (The principal exception was his brief use of prospect theory.) He would have tightened an already strong argument if he had justified his selection of bounded rationality more fully or decided to build his argument on a rational choice foundation.

Despite these quibbles, The Political Economy of Expertise represents a significant contribution to our understanding of the role that specialized knowledge plays in legislative policymaking. Kevin Esterling's work helps to explain and at least partially resolve the paradox of Congress's enduring investment in policy knowledge.