Standing in a Crowded Room: Exploring the Relation between Interest Group System Density and Access to Policymakers

• DOI: 10.1177/1065912919865938
• Date: 01 March 2020
• Published date: 01 March 2020
• Subject Matter: Articles

865938PRQXXX10.1177/1065912919865938Political Research QuarterlyHanegraaff et al.
research-article2019
Article
Political Research Quarterly
2020, Vol. 73(1) 51 –64
Standing in a Crowded Room:
© 2019 University of Utah
Article reuse guidelines:
Exploring the Relation between
https://doi.org/10.1177/1065912919865938
sagepub.com/journals-permissions
DOI: 10.1177/1065912919865938
Interest Group System Density
journals.sagepub.com/home/prq
and Access to Policymakers
Marcel Hanegraaff1, Jens van der Ploeg2, and Joost Berkhout1
Abstract
The numerous presence of interest groups may be a recipe for policy deadlock or, more optimistically, indicate the
vibrancy of a political community. Population-ecology theory suggests that the number of interest groups active in
a policy domain is relevant for strategies and political outcomes, such as policy access, and interest group density is
expected to reduce access for individual organizations. Competitive pressures in dense domains necessitate groups
to specialize to gain access to the policy access. We empirically assess this argument and indeed find lower levels
of access in denser policy fields, moderated by specialization of organizations in lobbying. Furthermore, we identify
important differences between mature (the Netherlands and Belgium) and young (Slovenia and Lithuania) interest
group systems. These findings address theoretical concerns about the lack of linkages between micro- and macro-
studies on interest representation.
Keywords
interest groups, civil society and voluntary groups, comparative politics, European politics, lobbying
Introduction
validate the importance of their work, scholars in the pop-
ulation ecology field routinely assume that the structure
The political science subfield of the study of interest
of interest group communities substantially affects “the
groups is split between macro- and micro-level studies.
use of influence tools” by interest groups (Lowery and
On one hand, the most prominent of the macro-level theo-
Gray 2004, 167) and “access to the policymaking pro-
ries is the population ecology theory, initiated by Gray and
cess” (Lowery and Gray 2015, 6). Yet, there are hardly
Lowery (1996), which is currently applied broadly in the
any empirical examinations of these assumptions. This
discipline of political science. Studies in this field explain
means that it remains unclear what the actual added value
the shape of interest group populations in terms of their
of the population ecology theory is for the broader politi-
density and diversity. These aggregate numbers have
cal science literature. Second, the absence of a link
macro-level implications related to representation (e.g.,
between macro- and micro-level studies is a problem for
related to representational biases), policy making (e.g., as
the latter type of studies as well, as they potentially suffer
cause of policy deadlock), or social stability (e.g., as a
from omitted variable bias or have external validity prob-
source of social cohesion). Micro-level studies, on the
lems. That is, particular micro-level lobby behaviors are
other hand, aim to explain variations in the strategies and
likely to be better explained when accounting for particu-
influence of individual interest groups. Such behaviors
lar macro-level contextual factors such as the number of
and outcomes are predominantly explained on the basis of
similar groups in a particular policy domain or system.
indicators such as resources spent on lobbying, the types
Population-related factors also affect the external validity
of interests represented, and issue and venue characteris-
tics (e.g., Bouwen 2004). Both theoretical foci have added
1University of Amsterdam, The Netherlands
much to the discipline and jointly form a relevant research
2University of Copenhagen, Denmark
community, but unfortunately hardly maintain effective
conceptual linkages to each other (Halpin and Jordan
Corresponding Author:
Joost Berkhout, Department of Political Science, University of
2012; Holyoke 2017; Lowery 2015).
Amsterdam, Nieuwe Achtergracht 166, 1012 DL Amsterdam, The
This overall lack of linkages between the two types of
Netherlands.
studies is problematic for at least two reasons. First, to
Email: d.j.berkhout@uva.nl

---

52
Political Research Quarterly 73(1)
of single-domain or single-system research designs. We
the vibrant group system based on competition and inde-
therefore concur with Holyoke (2017, also see Holyoke
pendence from the state.” Schattschneider (1960) and
2015) when he notes that “the bifurcation of today’s inter-
Olson (1982), by contrast, worried about the unintended
est group literature between these two levels of analysis is
effects of the indeterminate growth of interest group
a serious concern for theory development, research
activity. They warned that control over public policy by
design, statistical modeling, and general progress in the
narrow-interest, self-serving groups, increases with the
subfield” (see also Baumgartner and Shoub 2015, 221;
number of groups present, and, according to Olson, such
Leech 2015, 197; Lowery, Halpin, and Gray 2015, 267).
control will limit economic growth and ultimately lead to
In this paper, we therefore aim to make a start in
a decline of social and economic welfare.
addressing this concern by innovatively analyzing
Despite widespread attention, however, it was not
whether the density of interest group systems affects the
until the late 1980s that researchers started to systemati-
access groups have to political actors. In addition, we
cally analyze interest group systems as organizational
analyze whether population ecology theory provides us
populations. Gray and Lowery’s work stands out in this
the necessary tools to explain which types of organiza-
regard. Their study on the populations of interest groups
tions persevere in dense communities (e.g., more special-
in the states of the United States has become a distinct
ized groups) and which are more likely to be excluded
subfield within the interest group literature. Especially
from the political process (e.g., encompassing groups).
innovative was the application of theories derived from
Empirically, we rely on a novel data set of more than
biology, most prominently population ecology theory, to
three thousand organizations to test our assertions. This
explain how interest group systems evolve over time and
data set consists of various similar survey projects across
to explain their density and diversity at particular
different countries (namely, Belgium, the Netherlands,
moments in time. Their work has been highly influential
Slovenia, and Lithuania). In each of these countries, we
to many scholars studying interest group populations in
have data on the structure of the interest group systems
the decades following their 1996 book (for overviews,
per policy domain and the access individual interest
see Hojnacki et al. 2012; Lowery and Gray 2015).
groups have to the policy process. Combined, this allows
While its impact on the literature on interest group
us to test whether macro-level population characteristics
populations can hardly be overstated, the research did not
affect individual political outcomes, and whether these
fully live up to its initial promise. In Gray and Lowery’s
mechanisms follow the logic of population ecology
early work, they identified great potential for the popula-
theory.
tion ecology theory to “provide us new opportunities to
In what follows, we first describe how macro-level
theoretically link micro- and institutional-level analyses
studies of interest group communities are linked to stud-
of interest groups” (Lowery and Gray 1995, 25). More
ies of individual interest group behavior. Second, we pro-
specifically, they stated, “the most important opportuni-
vide hypotheses related to density and access gained, all
ties for future research may entail examining . . . implica-
derived from the organizational ecology literature. We
tions of our population level findings for the survival,
then describe our data collection strategy and test our
influence strategies, and life histories of individual orga-
hypotheses. We end with a reflection on the findings and
nizations” (Gray and Lowery 1996, 249–50). Yet, in
provide suggestions for additional research.
recent work, Lowery and Gray (2015, 7) themselves have
admitted that the latter objectives have not really been
The Link between Macro- and Micro-
achieved and are still “an area of organizational ecology
level Studies of Interest Groups
we have only begun to explore.” Holyoke (2015) regards
this lack of integration as a serious concern for theory
For over a century, social and political scientists have
development, research design, statistical modeling, and
theorized about the size of interest group populations and
general progress in the subfield. Loomis (2015) has been
its consequences for political stability, economic welfare,
even more outspoken and has questioned whether the
and “unbiased” political decision making. Truman (1951)
links between this macro-level work and micro-level
already noted over sixty years ago that the number of
research are currently so fuzzy that the former might not
interest groups has a direct effect on the stability of politi-
contribute much to the interest group literature at all.
cal systems, as they provide the...