Environmental Policy Convergence:
The Impact of International
Harmonization, Transnational
Communication, and Regulatory
Competition
Katharina Holzinger, Christoph Knill, and
Thomas Sommerer
Abstract In recent years, there is growing interest in the study of cross-national
policy convergence+ Yet we still have a limited understanding of the phenomenon:
Do we observe convergence of policies at all? Under which conditions can we expect
that domestic policies converge or rather develop fur ther apart? In this article, we
address this research deficit+ From a theoretical perspective, we concentrate on the
explanatory power of three factors, namely international harmonization, transna-
tional communication, and regulatory competition+ In empirical terms, we analyze if
and to what extent we can observe convergence of environmental policies across
twenty-four industrialized countries between 1970 and 2000+ We find an impressive
degree of environmental policy convergence between the countries under investiga-
tion+ This development is mainly caused by international harmonization and, to a
considerable degree, also by transnational communication, whereas regulatory com-
petition does not seem to play a role+
It became obvious with the fourth report of the Intergovernmental Panel on Cli-
mate Change
1
in spring 2007 that the need to combat climate change and to deal
with its consequences is one of the world’s most pressing problems+ Because the
human contribution to climate change is related to a broad range of activities,
such as energy use and production, transport, industrial and agrarian production,
and tropical deforestation, combating it—through the reduction of greenhouse gas
emissions—is not only costly but also requires profound behavioral changes+ More-
over, the global nature of the climate problem underlines the need for inter-
The research was supported by the EU, RTD program “Improving the human research potential and
the socio-economic knowledge base,” Contract No+ HPSE-CT-2002-00103+ We would like to thank the
reviewers and, in par ticular, the editors of IO, for many valuable comments+
1+ IPCC 2007+
First publ. in: International Organization 62 (2008), 4, pp. 553-587
Konstanzer Online-Publikations-System (KOPS)
URN: http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-76851
URL: http://kops.ub.uni-konstanz.de/volltexte/2009/7685
national coordination and cooperation, despite the fact that nation-states remain
the central actors for developing and implementing the respective policies+ States
react differently to the challenges of climate change+ Some are rather active, such
as most of the European Union ~EU! member states, while others are more hes-
itant, such as the United States and China+
Transnational environmental problems are not new+ They were acknowledged
for the first time during the 1970s and triggered supranational and international
action+ Given the transboundary character of most environmental problems , the
EU sought to harmonize environmental standards among its members+ Although
many international regimes dealing with environmental problems were estab-
lished, they rarely obliged nation states to introduce the same environmental pol-
icies+ Signing an international environmental agreement is a voluntary decision,
and the provisions of such a treaty usually leave much leeway for national
implementation—which is true even in the case of the EU+
In the first era of environmental policy, states reacted differently to the chal-
lenges, just as they do with climate change+ While some countries progressively
developed their own environmental policies, such as the United States, Japan, or
Germany, others lagged behind+ While some supra- and international measures con-
tained legally binding requirements for their members to develop respective policy
responses, other regimes induced countries to act by means of soft policy sugges-
tions+ Moreover, there seemed to be a “contagion” effect+ Environmental policies
diffused among the developed world+ Regardless of the driving forces at work ~prob-
lem pressure, political or normative pressure , or the incentive “to jump on the band-
wagon”!, countries observed each other’s policies and mutual learning took place+
So far, however, we know neither to what degree the environmental policies of
developed countries actually became more similar nor do we have systematic infor-
mation on the direction in which the contagion effect led+ Did environmental pol-
icies become more comprehensive and strict over the first thir ty years? Or did
they—in conjunction with the increasing integration of international markets —
develop downward, as the theory of regulatory competition would suggest? Finally,
we have limited knowledge about the causes and mechanisms that are responsi-
ble for these movements; that is, are they driven by international harmonization,
mutual policy learning and communication, economic integration and competi-
tion, or are they merely responses to domestic factors, such as political demand
and environmental movements? Knowledge about the mechanisms that drive the
diffusion of policies can help us deal with the challenges of the next era of envi-
ronmental policy+
Work on the diffusion of ideas, institutional and legal structures, organizations,
and policies as well as the underlying causes of diffusion and potential conver-
gence effects has recently become a major subject in political science+
2
The
2+ See Acharya 2004; Levi-Faur 2005; Elkins, Guzman, and Simmons 2006; Lee and Strang 2006;
and Swank 2006+
554
increased interest is evident, for example, in the recent symposium issue “Diffu-
sion of Liberalism” of this journal
3
or the special issue “Cross-national Policy
Convergence: Causes, Concepts and Empirical Findings” of the Journal of Euro-
pean Public Policy+
4
The diffusion of policies can be expected to result in an increase of policy
homogeneity among countries+ So far, however, there is no clear picture of the
extent of convergence+ While there are some indicators, these “trends are neither
universal nor uniform+ Variation occurs from issue-area to issue-area+”
5
More-
over, convergence as such is not the only or main subject of interest; it is also
the direction of the parallel change that matters and is often highly debated+ Using
a database covering the world from 1972 to 1996, Brinks and Coppedge find that
neighbor emulation plays a huge role in regime change+
6
The authors speak of
the third wave of democratization to show that growing more similar may also
mean that there is change in a certain direction— a common move toward more
democracy in this case+ However, the direction of change need not always be
associated with “more” or “better” structures or policies, as suggested by the expec-
tation and evidence of a downward spiral in tax competition or the downsizing
of the public sector+
7
Apart from the effects of diffusion on convergence and the parallel develop-
ment of countries, its causes are also of interest+ Does the strong growth of eco-
nomic and institutional linkages between nation-states lead to increasingly similar
policy measures across countries? Or are national responses to global or Euro-
pean challenges primarily influenced by existing domestic structures and institu-
tions?
8
Under which conditions can we expect domestic policies to converge or
to diverge? What explains the adoption of similar policies across countries over
time? If it exists, is the convergence of policies driven by economic processes,
by the rise of regional and global political institutions, or by endogenous national
policy choices? Although many factors have been suggested in the literature, there
is still a lack of systematic theoretical and empirical investigation about their
actual explanatory relevance+
In this article, we address this research deficit+ In empirical terms, we ask whether
the cross-national convergence of environmental policies can be observed+ We ana-
lyze the development of forty environmental measures across twenty-four coun-
tries between 1970 and 2000+ From a theoretical perspective, we are interested in
the explanatory power of three international factors often mentioned as impor tant
causes of policy convergence, namely international harmonization, transnational
communication, and regulatory competition+ However, we also account for a num-
3+ International Organization 2006: 60 ~4!+
4+ Journal of European Public Policy 2005: 12 ~5!+
5+ Kahler and Lake 2003, 2+
6+ Brinks and Coppedge 2006+
7+ See Swank 2006; and Lee and Strang 2006+
8+ Knill 2001+
555
ber of domestic factors, such as income, the pressure of environmental problems,
and political demand for environmental policy+
We define policy convergence as any increase in the similarity between one or
more characteristics of a cer tain policy ~for example, the exact policy settings! or
in the similarity of the policy repertoire in a certain field ~such as environmental
policy! across a given set of political jurisdictions ~such as states! over a given
period of time+ Policy convergence thus describes the end result of a process of
policy change over time toward some common point+
9
In this contribution we use
the concept of sigma-convergence focusing on the degree of similarity increases+
Theory and Hypotheses
In the literature, international factors play an important role in accounting for
cross-national policy convergence+
10
On the one hand, these factors refer to the
extent to which countries are institutionally interlinked+ In this context, emphasis
is placed not only on convergence effects emanating from the harmonization of
national policies through international or supranational law, but also on the effects
of transnational communication and information exchange within institutional-
ized networks+ On the other hand, regulatory competition emerging from increas-
ing economic integration was identified as an important factor that promotes the
mutual adjustment of policies across countries+ In focusing on the explanatory
relevance of these international factors, we do not neglect the potential influence
emerging from domestic factors+ Similarity or convergence of national conditions
might trigger similar political responses and hence policy convergence+
11
International Harmonization
International harmonization refers to a specific outcome of international coopera-
tion, namely to constellations in which national governments are legally required
to adopt policies that are in line with international legal requirements + Inter-
national harmonization presupposes the existence of interdependencies or exter-
nalities that push governments to resolve common problems through cooperation
within international institutions, and hence sacrifice some independence for the
good of the community+
12
Once established, institutional arrangements constrain
and shape domestic policy choices+ This way, international institutions are not only
the object of state choice, they also have consequences for subsequent governmen-
9+ Knill 2005, 768+
10+ See Hoberg 2001; Holzinger and Knill 2005; Simmons and Elkins 2004; and Simmons, Dobbin,
and Garrett 2006+
11+ Bennett 1991, 231+
12+ Hoberg 2001, 127+
556
tal activities+
13
However, the existence of an international provision does not auto-
matically imply similar provisions at the national level, because there is usually
much leeway in international treaties as well as deficient implementation of supra-
national law+
In the case of international cooperation, it may be argued that it is not the inter-
national institution that shapes, via its obligations, the member states’ policies and
thus leads to convergence, but that countries with the same policy preferences join
the same institutions+ This would certainly not be true for international organiza-
tions that cover a broad range of policy areas, such as the EU, the UN, or the
Organization for Economic Cooperation and Development ~OECD!+ Countries
would not join this organization just because they have similar environmental pol-
icy preferences+ It might be true, however, for single-issue environmental treaties+
The causal direction would thus be the other way around, implying that we might
face a problem of endogeneity+
However, having the same policy preferences is not the same as having the same
policies+ As we have outlined, international environmental treaties are typically
concluded in order to avoid spatial externalities and to provide global public goods+
In undertaking international cooperation, members aim at binding themselves and
others to a policy they all deem desirable but would otherwise probably not adopt
because there are considerable incentives to a free ride+ Having the same policy
preference is hence not a sufficient condition for having the same policies+ Inter-
national harmonization has a distinctive causal role to play+ For this reason the
problem of endogeneity does not seem to pose a severe challenge+
To grasp the influence of international harmonization on policy convergence,
we distinguish between two types of harmonization effects+ On the one hand, these
effects arise from accession: members ratify the treaty and have to comply with
the respective requirements, implying that convergence effects occur only once+
On the other hand, we can also conceive of harmonization effects through mem-
bership, if the institution in question has the competence and authority to produce
regulatory output for its members, which leads to enduring and steadily renewed
harmonization effects over time+ In contrast to most international institutions, the
particular character of the EU implies harmonization effects from membership, as
the institutions of the EU continuously develop and decide upon new legislative
proposals+ For other international institutions, harmonization effects basically
emerge from accession+
Moreover, international institutions crucially differ in their obligatory potential,
that is, the extent to which compliance with legal obligations can actually be
enforced+ In the EU, such powers are comparatively well developed, given the
direct effect and the supremacy of European law+ International institutions, by con-
trast, not only lack these characteristics of enforcement power—they also reveal
13+ Martin and Simmons 1998, 743+
557
