In the crowded Washington interest group community, lobbyists have to compete with one another to influence policy in their areas of concern. Thomas Holyoke demonstrates that this competition can sometimes produce compromise, depending on the ideological alignment of groups and legislators and the flexibility that members give group leaders. By cleverly assembling data from 83 interviews and close analysis of six policy debates, he investigates the conditions under which lobbyists and legislators reach consensus on policy proposals rather than maintain polarized positions.

Holyoke compiles the positions that lobbyists and legislators advocate on arctic oil drilling, bankruptcy reform, bioengineered food, wildlife conservation, dairy pricing, and money laundering from 1999 to 2002 in the US Congress. His innovation is to rank the proposed options in each issue area from most liberal to most conservative. By asking the lobbyists to identify their ideal resolution as well as any other proposals that they support along each continuum, he can estimate how far interest groups are willing to compromise and whether their choices affect a bill's chance to become law.

The results indicate that lobbyists are more willing to support compromise positions if their membership is flexible, their opponents are numerous and resourceful, and their target legislators support proposals further from their preferred option. Lobbyists are also most likely to cooperate on the proposals advocated by their more resourceful and committed competitors, but also by those who more closely share their preferences. Public interest groups and organizations with larger lobbying forces are less likely to support compromise positions in each case. Compromises among legislators are only sometimes associated with interest-group cooperation. Nonetheless, bills with support from moderate legislators are more likely to reduce ideological conflict among interest groups; in turn, more compromise among interest groups is associated with more bills becoming law.

The results come from four different data sets, each with its own unit of analysis but much of the same data. The first study assesses whether each group supports each compromise proposal (at the group-proposal level of analysis), the second whether each pair of groups cooperates in support of the same proposal (at the dyad level), the third whether the average divisions between groups atrophy as proposals move through committees (at the issue level), and the fourth whether group divisions lead to less advancement of legislation (at the bill level). This mixture of analyses is a virtue of the book because it provides the reader several lenses through which to see the same underlying process.

The problem is that the most important patterns may happen at the issue level of analysis, where only six cases are available. The first analysis assumes that one can independently observe each group's decision on each proposal and the second that each dyad independently decides whether or not to cooperate. Yet no lobbyist decision is independent of issue-level dynamics or the decisions of all the others. In one issue area, hundreds of lobbyists reach agreement; in others, there is little movement. Twice as many wildlife conservation lobbyists, for example, adopt compromise positions as those in any other issue area. Money-laundering reform lobbyists remain equally divided in their ideal and advocated positions, whereas all of the other issue areas feature some compromise. There are no bills enacted to address bankruptcy reform or arctic drilling but quite a few in the other four areas.

Holyoke explores several issue-level mechanisms for these differences; he assesses distinct dynamics due to issue salience and type, as well as party and committee polarization. He theorizes about possible cascading bandwagons of support and the role of networking among lobbyists and legislators. Without enough issue areas to observe, however, the reader is left wondering why compromise seems so much more obtainable in some issue areas than in others. Interest groups may have little to do with the potential to compromise in some areas. Alternatively, their divisions may be symptomatic of the same precursors that lead legislators to deal on some issues and fight it out on others. Holyoke gathers evidence that interest groups play a role, but their decisions are constrained by the availability of reasonable, moderate proposals that legislators advocate. Much of the art of politics is finding a proposal that satisfies as many people as possible. The context of each issue area determines the difficulty of that task. Interest groups may be primary or secondary participants in the process of finding acceptable compromises.

Holyoke models interest-group strategy as an outcome of competition in ideological space. He effectively dispenses with older views of interest groups as partners in cozy subgovernments or seekers of niches without any opponents. To get what they want, most lobbyists need to convince legislators to accept their views and disregard those of other groups. The author proposes that the primary challenge of a lobbyist is trying to satisfy his or her members, as well as legislators. Some lobbyists have more leeway from members and some have stronger competition; either can promote compromise. Lobbyists often need to move toward the proposals of legislators rather than visa versa. A lobbyist's decision to join a coalition, previously seen mostly as a resource-sharing arrangement, is seen here as a choice of endorsing a potential compromise. In Holyoke's view, all of this leaves open more potential for groups to deliberate with their members and with other groups—to reach consensus, not aid gridlock.

The empirical work points to a few limitations of this theoretical view. First, lobbyists support proposals different from their ideal position in only about one-third of the cases (and less than one-fifth in most issue areas); there is quite a bit of sincere lobbying that may not be very strategic. Second, the analysis happens to include mostly membership organizations; memberless advocacy groups, corporate policy offices, and other institutions may operate more opportunistically. Third, it is difficult to separate empirically the desire to satisfy members from personal intransigence or ideological commitment. Likewise, a lobbyist may move toward legislators to influence a bill's passage or to maintain access; we only observe the movement. Fourth, not all issues may be best understood as a unidimensional ideological battle with several intermediary positions, even if these six can be viewed that way. Fifth, although the analysis admirably attempts to sort out whether legislator or interest-group compromises come first, the results show issue-specific feedback loops where neither is the definitive first mover.

This book is an impressive addition to the contemporary interest-group literature. It is well worth reading by the broader audience interested in American lawmaking and policy dynamics. It is also a marker of the successful evolution of interest-group research, from a concern with those who mobilize and those who dominate to coverage of the specific choices that lobbyists make as actors interdependent with one another and with policymakers. The book illustrates how competitive pressures are inseparable from the policies that groups advocate and their potential for influence. Interest groups can mirror the broader political system, either in reaching consensus on compromise proposals or in polarizing and thus enabling gridlock. Competitive Interests shows that they do both, illustrating some of the mechanisms driving each process.