Aside from a chapter that contains a regression model to test the response of trust fund and general revenues to political and institutional factors, the empirical focus is on case histories of five trust funds—Social Security, Hospital Insurance, Highway, Airport and Airways, and the Superfund. Also examined are the failed attempts to create trust funds for energy security and lead paint abatement. The regression analysis shows that political forces have differential effects on trust fund revenues and general revenues. This chapter is somewhat unrelated to the case histories, which are more central to the book's main objectives, that is, to explain the origin, evolution, and consequences of trust funds. Using the historical-institutionalist method, Patashnik draws out the variations among trust funds, the common traits, and the nuances in their design and evolution.

Patashnik's central argument is that trust funds are intentionally designed policy instruments that seek to provide durability and reduce uncertainty over spending and revenue decisions. They are created when program advocates convince others that establishing a long-term commitment to a program is better than maintaining the flexibility to make ongoing policy adjustments. Among the four distinct rationales for trust funds (making users pay, maximizing budgets, reducing uncertainty, and guarding the Treasury), reduced political uncertainty is found to be most important in all the cases (p. 189). Program advocates for each trust fund demonstrated the value of locking in policy commitments and the need to bind future policymakers. Conversely, in the energy security and lead paint abatement cases, advocates were unable to demonstrate that a trust fund was needed to make the programs work or that a long-term commitment was preferable to preserving flexibility.

By dedicating revenues to a specific purpose for both present needs and future contingencies, trust funds create an implicit contract and define the terms for subsequent policy debates. In this respect, they are similar to entitlements and indexation because they contain procedural safeguards, have greater autonomy than routine programs, and provoke symbolic sensitivities that limit the flexibility of policymakers.

Patashnik deftly points out, however, that although trust funds constrain future choices, the programs financed by them are neither insulated from politics nor impervious to change. The programs are typically financed on a pay-as-you-go basis, and they are challenged by threats of insolvency, new ideas, pressures from interest groups, or changes in institutional procedures. The durability of trust funds rests on their capacity to serve a mediating role in policy debates. “Trust fund financing clearly does not eliminate the impact of other political forces, such as struggles among contending groups. But trust funds do influence how those struggles are played out by distributing procedural advantages, reinforcing symbols of moral deservedness and blame, and affecting perceptions of political fidelity and defection” (p. 16).

Patashnik also describes the variation in the design features, autonomy, and durability of trust funds. Social Security is the most durable because individual beneficiaries rely heavily on the government to make good on the program's promise. The Hospital Insurance Trust Fund for Medicare, which is as politically potent as Social Security, is less stable partly because it is more reliant on general funds. The Highway Trust Fund's durability relies on the support of a nexus of producer groups, government officials, and motorists, but it has a low degree of individual beneficiary reliance and periodically has been challenged by budget guardians, environmentalists, and urban mass transit interests.

Despite the variation among trust funds, Patashnik identifies four common attributes that distinguish successful adoption: a base of support for the expenditure program, plausibility in terms of a precedent and an appropriate revenue source, a demonstration that trust fund financing is necessary to make the program work, and neutralization of opposition to the idea (pp. 183–6). Trust funds often are supported both by program advocates, who want the program protected from the vicissitudes of the annual budget process, and by fiscal conservatives, who view the mechanism as a means of cost control.

Patashnik's insights into the politics of trust fund budgeting contribute significant new knowledge, but the theoretical aspects of the book should not be overlooked. The author effectively points out the shortcomings of the policy inheritance perspective, which views policymakers as severely constrained by their predecessors, and rational choice theory, which argues that institutional structure dictates policy. Patashnik shows that institutional arrangements mediate rather than cause policy outcomes; that policymaking is an evolutionary process and programs are responsive to historical nuances and acts of individual policymakers; and that ideas, not just interests, are critical forces in the resolution of policy conflicts.

In terms of the design and durability of trust funds, Patashnik finds that both competing theories of political transaction costs are incomplete. One of these contends that institutions are efficient and inherent to government, and the other maintains that costs are inflated and contrived to serve the narrow interests of politicians. Either theory might lead us to expect that more trust funds would have been adopted over the years. Yet, not only do agencies such as the Congressional Budget Office and the Office of Management and Budget fight to limit trust funds in order to maintain as much flexibility as possible over annual spending and revenue decisions, but also “Congress itself seems to exercise a degree of collective self-restraint” (p. 193). Patashnik notes that “trust fund advocates rarely can win merely by asserting their narrow mutual interests…. Given the multiplicity of veto points in the U.S. system, it is difficult for a coalition to get its structural projects enacted without fairly board support, and other factions cannot be expected to share the former group's parochial interests” (p. 195).

The only shortcoming is the very limited effort at the end to consider the normative challenges to trust funds. Serious consideration of these matters would require at least another chapter. Yet, any suggestions about what could have been done take nothing away from what has been done. Patashnik's study is a very important contribution to the literature on budgetary politics and policymaking generally. Some may wish for a more parsimonious explanation of the origin and evolution of trust funds, but political scientists would not be better off for it.