Evaluating the case study literature and directions for future research
Case studies show how aggregate constraints are translated into group- level change, and that organized interests have quite a bit of agency in responses to resource pressures. In addition, as I discuss here, the case study literature shows that some of the concepts that are taken as a "given" in the population ecology literature are actually subject to change by organized interests, and thus raises important questions for future research. I also explain, however, that the case study literature suffers from a somewhat limited empirical scope. Furthermore, adopting a more explicit and systematic consideration of how the survival goal shapes group behavior could better connect the case study literature with the broader population ecology literature on interest representation and make case studies more relevant to important theoretical and empirical debates in the study of organized interests going forward.
The malleability of guilds, niches and environments
One major insight emerging from the case study literature is that many of the concepts that are taken as fixed and exogenously determined in population ecology can in fact be changed by organized interests. In population ecology, the type of organism that an animal is and the environment that it exists in - an ecosystem and a niche within a particular ecosystem - are usually taken as given and stable (Gray and Lowery 1996). This makes a lot of sense in nature where most organisms cannot change their niche and certainly cannot change their species. However, the case study literature shows that groups can change their niche, ecosystem and even what type of group (organism) they are. These findings suggest more complexity in the application of population ecology concepts to human organizations than is often acknowledged.
In the population-level studies, the guild or sector that a group belongs to is taken as an objective fact. For instance, groups that claim to represent the rights of LGBT people are LGBT groups (Nownes and Lipinski 2005). This view also appears in the case study literature. For instance, Meyer and Imig (1993, 258) write that "interest group sectors are composed of the set of organized groups that share broadly similar policy goals." But, "broadly similar" is vague and case studies show that group policy goals, niches and organizational forms change over time.
Almost all groups have multidimensional policy goals and identities (Heaney 2007) and thus organizations have some choice about which guild they belong to and the niche they reside in. In terms of policy niches or sectors, group missions can change over time or across circumstances. For instance, LGBT groups can branch out into other issues, or groups that are not primarily identified as LGBT groups will sometimes advocate on behalf of LGBT interests. Conservative Christian organizations were formed and mobilized around social issues, but these groups have branched out into economic issues (Rozell and Wilcox 1996). Similarly, unions that were mobilized around bread and butter issues were instrumental in advancing civil rights legislation, and recently they have begun to adopt positions on issues like abortion (Dark 1999). Given this diversity, assigning groups to a single guild is somewhat artificial.
Even more fundamental than transforming the guild or niche they belong in, organized interests can completely change the environment they exist in, in two ways. First, organized interests are able to shape the total amount of resources in the environment in a way that is impossible for many organisms in nature. Organized interests often lobby precisely for more money to support groups in their sector or guild (Imig 1992). Or groups lobby for policies that make it easier to gain members, as when unions lobby for laws that facilitate union organizing (Dark 1999) or the Farm Bureau lobbies for agriculture price supports that provide more money to farmers to support the activities of the Farm Bureau (Hansen 1991). It is sometimes useful to view the total available resources as exogenously fixed, but this is not really the case over the long-term for organized interests, and it suggests an interesting area of study for future research.
Second, while many organisms are mobile, organized interests have the self-conscious ability to move to an entirely different "ecosystem" which many organisms in nature lack. This mobility is especially apparent in any layered system of government (e.g. supra-national organizations like the European Union, or federalist countries like the US). Gray and Lowery (1996) largely take the polity that a group exists in as a given in their studies and ignore the fact that groups can move to different states, or lobby the federal or local government to achieve policy goals (they do address this in other work, e.g. Baumgartner et al. 2009). But organized interests can shift between governments to secure needed resources. The Christian Right began to gain power in states with many evangelical Christians, and only later emerged as a force nationally (Green et al. 2003; Rozell and Wilcox 1996).
In addition to this "vertical mobility," organized interests can engage in "horizontal mobility" by switching or expanding their geographical location to find needed resources. For an example of the latter, Hansen (1991) notes that the Farm Bureau had a more national membership base than other farm groups active in the 1920s and 1930s. These different geographical bases of support reflect that some farm groups sought to form a base to influence state politics (which was the important locus of decision-making in economic policy in the late 1800s) in some states and not others. This "venue shopping" has been examined from an organized interests influence perspective (Baumgartner and Jones 1993), but how the availability of resources may affect venue shopping is an interesting question to be explored.
One final challenge to the idea of interest group guilds and niches is that, unlike most animals in nature, groups can completely change the type of "organism" that they are. In their study of the Soil Association in the United Kingdom, Halpin, Daugbjerg and Schvartzman (2011) argue that groups go well beyond tinkering with their issue focus to redefine their niche - at times in response to a changing external environment, groups undergo "radical" organizational changes. The Soil Association shifted from a scientific society to an advocacy organization.
