Membership in International Organizations

Most of the literature on international integration and the provision of environmental quality focuses solely on economic facets of international integration, such as tradeFootnote 5 and foreign direct investment (FDI).Footnote 6 Few studies have taken the political dimension of globalization into account. A notable exception is that by Ward, who examines whether countries that are more central to the network of international environmental regimes act more sustainably at the national level.Footnote 7 Using social network analysis, he finds that more central countries indeed care more about domestic environmental quality. Although his study concentrates on the network of international environmental treaties and organizations, he notes:

Following Ward, I propose to analyse the impact of IGO membership on a country's willingness to take care and capability of taking care of its environment. Thereby, I evaluate whether the inclusion of the political aspect of international integration, in addition to the economic facets of globalization, adds to our understanding of environmental quality in developing countries.

The general purpose of intergovernmental organizationsFootnote 11 is to facilitate co-operation at the international level and thereby enable countries to solve problems that they often are unable to solve independently, thus realizing benefits from mutual co-operation.Footnote 12 IGOs promote co-operation by reducing transaction costs, decreasing uncertainty, strengthening the shadow of the future, increasing reputational costs and by allowing credible commitments.Footnote 13 Consequently, I argue that membership in IGOs may influence the environmental performance of developing countries for the following reasons:Footnote 14

1. (1) At least in principle, IGOs can compel member states to obey their rules by raising the reputational stakes for reneging on agreements.Footnote 15 In addition, many IGOs establish non-compliance procedures such as sanctions that can help enforce conformity with the rules of the organization. Note, however, that this will directly affect environmental quality only in the case of IGOs that have some environmental purposes, such as the Multilateral Fund for the Implementation of the Montreal Protocol or the North Atlantic Salmon Conservation Organization.

2. (2) IGOs create norms defining good behaviour – or rather what constitutes bad conduct.Footnote 16 Although a specific IGO might not have been created with an explicit environmental mandate, the broader idea of environmental protection as being of importance might still spread through membership in this IGO. In this sense, international organizations can constitute a forum in which states and other actors that have an interest in environmental protection, such as environmental non-governmental organizations (ENGOs), can promote this idea and also influence other states. Hence, IGO membership can be important to socializing states in relation to environmental protection.

A pertinent example is sustainable development. In the last two decades many IGOs have taken up this issue. Although not all of these organizations actually provide developing countries with relevant technologies and resources, they increase both domestic awareness and international pressure for sustainable development. IGOs such as the Organization of American States or the African Union are examples of organizations that have passed declarations devoted to sustainable development, and the former has even established a department dealing with this issue, besides embracing the promotion of environmental quality.Footnote 17

This effect of IGO membership is also emphasized in the literature on policy diffusion. Cao, for example, shows that interactions at the international level through trade ties or connections in IGO networks, which serve as channels for information transfer, play a significant role in the socialization process among states.Footnote 18

1. (3) Even though countries become members of an IGO for specific reasons, e.g. financial assistance, they are also exposed to the other purposes of the organization, such as environmental protection. Examples include the World Bank and the European Union (EU). Jahn, for instance, posits that ‘membership in an international organization such as the EU may support the improvement of environmental standards. The rationale is that particular environmentally conscious countries take the role of pioneers that push environmental issues onto the agenda of countries that might be perceived as environmental laggards’.Footnote 19 The case of Laos corroborates this argument. By joining the Association of Southeast Asian Nations (ASEAN) in 1997, Laos was required to implement a number of agreements pertaining to making agri-economic development more sustainable, which as a side effect positively affected Laos's environment.Footnote 20

The three arguments above all refer to mechanisms through which IGOs might influence a country's willingness to enhance its environmental performance. In this sense, these arguments can equally pertain to both developing and developed countries. However, an additional argument suggests that membership in IGOs may especially affect the capability of developing countries to improve their environmental performance by allowing for information and technology transfer. This channel is especially important since developing countries often lack the necessary resources and technologies to combat environmental degradation.Footnote 21 Porter et al. argue that new information and knowledge about environmental pollution can create awareness of environmental quality as an important public good, and knowledge about technology for abatement could be distributed.Footnote 22 This implies that a country that is better ‘politically’ integrated in the international system could receive more relevant information and could more easily draw on technical knowledge and assistance from international organizations. Examples of IGOs that diffuse information and technologies that also benefit the environment are the World Bank, the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). The World Bank as part of its general ‘greening’ strategy created, together with some Western governments, the Global Environment Facility (GEF), which aims to provide mainly developing countries with grants and technical assistance to address environmental problems such as climate change, ozone depletion, biodiversity loss and pollution.Footnote 23 Similarly, the FAO's department dealing with natural resource management and environmental issues seeks to promote sustainable land and water use by providing technical assistance and research-driven knowledge on the best ways of achieving sustainable farming and the sustainable management of natural resources. In that way, the organization directly transfers technology and knowledge necessary to reduce environmental pollution to developing countries. Hence, although these organizations mostly pursue goals that are not motivated by environmental protection per se, such as access to safe drinking water and sustainable farming, they also provide technologies and know-how that are often conducive to protecting the environment.

Taken together, these arguments lead to the conjecture that membership in IGOs should positively influence the environmental performance of developing countries:

However, one could argue that not all international organizations can influence developing countries’ environmental performance to the same extent. Gartzke et al. note that IGOs differ with regard to their degree of institutionalization and thus with regard to their ‘ability to enact policies and decisions’.Footnote 24 Accordingly, the degree of institutionalization of an IGO may partly determine to what extent it has the capability to influence its members. That is, while IGOs whose ‘bureaucratic, executive, or judicial organs do not have any formalized power’Footnote 25 (minimally institutionalized IGOs) should lack the capability to strongly exert influence over their members, IGOs that ‘possess clear mechanisms for coercing or influencing state behaviour’Footnote 26 (strongly institutionalized IGOs) could in principle limit member states’ sovereignty and thus affect their policies.

Consequently, the influence channels of IGOs discussed above, such as issue linkage or the provision of knowledge and technology, should be more pronounced in those IGOs that are more institutionalized. In contrast, minimally institutionalized IGOs, which lack strong administrative structures and capabilities, might find it harder to provide resources in the form of knowledge and technology needed in developing countries to enhance their environmental performance. Hence, I expect that more institutionalized IGOs possess the institutional requirements to influence environmental quality in developing countries, whereas the influence of minimally institutionalized IGOs should not be so pronounced.

Domestic Factors

In addition to a country being influenced by its degree of international integration, there are important domestic factors that shape its environmental performance. The literature puts special emphasis on a country's income and its political system. Consequently, I will discuss these two factors in the following paragraphs and adapt the argument to the specific context of developing countries.

Variables

The motivation behind this article is to identify whether membership in IGOs can help developing countries curtail their environmental pollution. Although environmental regulation is often a necessary condition for improved environmental outcomes, several reasons have led me to focus exclusively on environmental quality measures. First, in contrast to domestic environmental policy outputs, environmental quality measures are in most cases easily comparable across countries, especially in the case of developing countries. Second, alongside country fixed effects, the empirical design controls for various factors such as economic growth and population structure that could potentially compromise governments’ ability to affect environmental quality. Third, it is usually the case that citizens care more about whether pollution is reduced than whether their government has enacted certain environmental regulations; therefore, environmental quality measures should be at the heart of this study.

In the literature, many different measures of environmental quality have been employed such as indicators of air quality,Footnote 41 water qualityFootnote 42 or indices that combine several measures of environmental quality such as the environmental sustainability index or the genuine savings index.Footnote 43 Unfortunately, the paucity of data that exists in time-series cross-section format limits the choice to sulphur dioxide (SO₂) and carbon dioxide (CO₂) emissions.Footnote 44 The two indicators are measured in levels instead of growth rates for two reasons. First, I consider levels as more appropriate, since all my arguments refer to the quality of the environment and not to changes in environmental performance. And, second, changes could be misleading in the sense that the growth rate of pollution may be high, implying bad environmental performance, whereas the overall state of the environment is still good; or growth rates may be low while the state of the environment is quite bad.

Both indicators proxy for important aspects of environmental quality: SO₂ is a primary contributor to acid rain and detrimental to human health and the well-being of the ecosystem. It mostly arises from burning fossil fuels such as coal or oil and is primarily emitted by power plants, petroleum refineries, metal processing facilities, locomotives and large ships. The data on SO₂ emissions are taken from Stern.Footnote 45 CO₂ is largely a by-product of energy production and use and is mainly released during the combustion of fossil fuels and cement manufacturing.Footnote 46 CO₂ emissions are the primary contributor to global warming and climate change since they account for the majority of greenhouse gases.Footnote 47 The data on CO₂ emissions come from the World Bank's Development Indicators.Footnote 48 Both SO₂ and CO₂ emissions are measured in thousand metric tons per capita in order to control for population size. I use the natural log of both variables because of their long right-tail distribution.

Theory suggests that developing countries that are members of more IGOs should emit less SO₂ and CO₂. However, the different natures of the two pollutants suggest that the effect could be stronger in the case of SO₂ and less pronounced in the case of CO₂. This is because SO₂, compared with CO₂, is a local air pollutant whose adverse effects on the environment and human health are felt locally. In contrast, the harm arising from CO₂ pollution is of a global nature, implying that governments need to co-ordinate in order to combat the effects of CO₂ emissions, which opens the possibility for free-riding behaviour. Furthermore, the effects of CO₂ emissions, such as climate change, are long term in nature, whereas SO₂ emissions have more short-term effects, such as acid rain. This might give governments an additional incentive to prioritize the abatement of SO₂ over CO₂ emissions. Hence, we might see a difference in the magnitude of the negative effects of IGO with the effect being bigger for SO₂.

The main independent variables of my analysis are a country's membership in intergovernmental organizations, its income and its political system. The first independent variable is operationalized as the yearly cumulative count of each country's IGO memberships. The data come from the Correlates of War Project (COW).Footnote 49 The use of this cumulative measure is appropriate as this acknowledges that being a member of a certain number of IGOs limits a country's options for further membership, whereas the number of new memberships per annum does not do so.

To evaluate the argument that more institutionalized IGOs may be more effective in influencing developing countries’ environmental performance than IGOs that only exist on paper, I rely on data from Boehmer et al.Footnote 50 They code three degrees of institutionalization: minimally, moderately and highly institutionalized IGOs.Footnote 51 Minimally institutionalized IGOs are organizations that ‘lack any bureaucratic, executive, or judicial organs that possess any formalized power’.Footnote 52 Medium institutionalization refers to organizations to which ‘member states relinquish minimal amounts of their sovereignty to support IGO projects and missions’Footnote 53, and highly institutionalized IGOs are organizations that ‘possess clear mechanisms for coercing or influencing state behavior’.Footnote 54

The political system of a country is operationalized using the combined Polity IV score ranging from 1 – most autocratic – to 21 – most democratic.Footnote 55 Polity IV captures the competitiveness of political participation, the guarantee of openness and competitiveness of executive recruitment, and the existence of institutionalized constraints on the exercise of executive power. Since Polity IV has been criticized with regard to its aggregation procedure,Footnote 56 I use two additional measures of democracy for robustness checks. First, I rely on the dichotomous index of democracy developed by Alvarez et al. (ACLP index)Footnote 57 and, second, I use Bueno de Mesquita's measure capturing the size of the winning coalition relative to the size of the selectorate.Footnote 58

To account for the effect of national income on pollution, the log of GDP per capita is included in the model. Although the logic of the environmental Kuznets curve suggests that both GDP per capita and its square term should be included in the regression model, doing so results in statistically insignificant estimated coefficients for both variables.Footnote 59 This is due to the fact that the analysis is restricted to developing countries. Here we should observe income negatively impacting on environmental performance.Footnote 60 Therefore, using a quadratic specification does not capture the theoretically expected relationship. The data on national income come from Gleditsch, which is an updated version of the Penn World Tables.Footnote 61

A number of control variables are also included in the statistical model. I control for the fact that a growing economy is often associated with environmental degradation. Since a larger population usually consumes more natural resources and thereby produces greater environmental degradation, population density is also included.Footnote 62

Several existing studies have examined the economic facets of globalization and their influence on environmental quality. To be able to separate the impact of international political integration from the economic aspects of international integration, I also include a country's trade openness and its foreign direct investment (FDI) inflows. The literature on economic globalization and provision of public goods contrasts arguments on general welfare enhancing gains with arguments on regulatory competition.Footnote 63 According to the first argument, stronger economic integration should have, on average, a positive effect on environmental quality because of the welfare enhancing gains of globalization. In particular, it is argued that increasing economic integration allows countries to specialize in industries in which they have a comparative advantage, making for a more efficient allocation of resources and higher productivity. As a result, a country's national income is supposed to increase, which then leads to higher public goods provision.Footnote 64 According to the second argument, increasing economic interdependence leads to strong regulatory competition between countries.Footnote 65 In order to increase their competitiveness and attract foreign capital, countries are pushed towards less stringent regulations, which can lead to either a regulatory chill or even to a race to the bottom that would undermine the provision of public goods such as environmental quality and social welfare benefits. Which of the two effects actually prevails is mainly an empirical question.Footnote 66 Trade openness is measured by the yearly ratio of the sum of exports and imports to GDP.Footnote 67 FDI inflows are measured in percent of GDP and the data are taken from the World Bank Development Indicators.

Finally, a time trend is added to the model in order to control for events such as technology improvements over time. Table 1 displays descriptive statistics of the variables used in the regression models.

Table 1

Descriptive Statistics

Note: Negative values for FDI net inflows per capita imply that more capital is going out of the country than coming into the country.

Empirical Results

To test the implications of my arguments empirically I use a fixed-effects estimation procedure with panel-corrected standard errors (PCSE) and a Prais–Winsten specification to control for autocorrelation. Since IGO membership effects may need some time to trickle through, all of the independent and control variables enter into the model with a one-year time lag.Footnote 68

Table 2 shows the results of testing Hypothesis 1, anticipating a positive relationship between IGO membership and environmental performance. As expected, membership in international organizations has a positive influence on the environmental performance of developing countries as measured by either of the two indicators.Footnote 69 Interestingly, the results do not show a distinct difference between the coefficient of IGO membership in the models for SO₂ and CO₂, although CO₂ emissions pose a more global and long-term threat, in contrast to SO₂ emissions, whose adverse effects are of a more local and short-term nature.

Table 2

IGO Membership and Environmental Quality

Note: Panel-corrected standard errors in parentheses; ***p < 0.01, **p < 0.05, *p < 0.1.

Country effects are not displayed in the regression table.

Columns 3 and 4 in Table 2 show the results when I disaggregate IGO membership according to the degree of institutionalization of the respective organizations. As expected, we see that minimally institutionalized organizations are never associated with a significant reduction in SO₂ and CO₂ emissions. Interestingly, however, it is not always the most institutionalized IGOs that are significantly associated with better environmental quality. As the results show, highly institutionalized IGOs are the most important organizations only in the case of SO₂ emissions. In the case of CO₂ emissions, those IGOs with a medium degree of institutionalization seem to be the most influential.

I infer from these findings that some degree of formalization or institutionalization of an organization is needed to affect environmental quality in developing countries. However, it is not necessarily the most institutionalized or powerful organizations, in the sense that they can constrain their member countries the most, that affect environmental quality in developing countries. This could be due to the fact that the main mechanisms behind the influence of IGOs – as proposed in the theoretical part of this article – are technology and knowledge transfer, issue linkage and a broader socialization process towards environmental protection. As long as they fulfil these purposes, organizations that possess some degree of institutionalization seem to be associated with better environmental quality in developing countries.

With regard to a country's income, we observe that an increase in GDP per capita is indeed associated with an increase in pollution as predicted by the EKC argument. This confirms the theoretical assertion that the countries in this sample have not yet reached that point on the EKC after which an increase in income would lead to improved environmental quality.

Finally, as argued in the theoretical part, democratic developing countries do not seem to perform better with regard to environmental quality, relative to their autocratic counterparts. The results show no statistically significant effect of the political regime type on either of the two indicators of environmental quality. These results are therefore compatible with the assertion that at the stage of early economic development, environmental quality is perceived as a luxury good, implying that citizens do not demand that their governments spend scarce resources on enhancing environmental quality.

Interestingly, none of the control variables exerts a robust influence. Population density is associated with an increase in CO₂ emissions but is not statistically significant for SO₂ emissions. Similarly, trade openness turns out to be significant only for CO₂ emissions, countries that are more open emitting more CO₂. Economic growth and foreign direct with investment, in contrast, are not significantly associated with either SO₂ or CO₂ emissions.

Further Disaggregation of IGO Membership

In addition to the degree of institutionalization, the function or purpose of a particular IGO might also be of importance. Although my theoretical arguments potentially apply to all types of IGO, some do seem likely to be more important for certain types than for others. For example, the possibility of issue linkage should be more pronounced in umbrella (multi-purpose) IGOs since they deal with a large variety of issues. Technology transfer, in contrast, should be more likely to occur in more technically oriented IGOs such as agrarian or nuclear IGOs. Furthermore, because of their precise thematic focus, environmental IGOs should clearly be interested in improving environmental quality in developing countries. Hence, defined by purpose, some types of IGOs may have a stronger influence than others.

Ingram et al. code IGOs according to their mandate into general umbrella, political, economic and social organizations.Footnote 70 I extended the time period covered by Ingram et al.'s coding to the year 2000.Footnote 71 The only exception I made to their coding instructions was that I created additional categories for nuclear and agrarian IGOs. Thus, IGOs were categorized as military (for instance, the North Atlantic Treaty Organization (NATO)), umbrella (for example, Association of Southeast Asian Nations (ASEAN), European Union (EU)), economic general (such as the World Trade Organization (WTO) and the International Monetary Fund (IMF)), economic co-operation (for example, the World Bank), economic industry specific (as in Cocoa Producers Alliance), economic standardization (for example, Caribbean Postal Union), social (such as the World Health Organization (WHO), the International Labour Office (ILO), the United Nations Educational, Scientific and Cultural Organization (UNESCO)), environmental (like the Global Environmental Facility (GEF)), nuclear (for example, the International Atomic Energy Agency (IAEA)), and agricultural (for instance, the Food and Agriculture Organization (FAO)) organizations.

Table 3 shows the results using the disaggregated IGO measure instead of the general count variable. Interestingly, only membership in umbrella, economic general and military IGOs exert a significantly negative effect on pollution for both environmental indicators while controlling for membership of other IGO types. Membership in social and nuclear IGOs is of importance only when considering SO₂, but it has no effect in the case of CO₂ emissions. In contrast, environmental and economic standardization IGOs are associated with lower CO₂, but not lower SO₂, emissions. Finally, economic co-operation, economic industry specific and agricultural IGOs are never linked to better environmental quality.

Table 3

Disaggregating IGO Membership

Note: Panel-corrected standard errors in parentheses; ***p < 0.01, **p < 0.05, *p < 0.1.

Country effects are not displayed in the regression table.

In addition to being interesting in its own right, disaggregating IGO membership can provide some intuition concerning the underlying mechanisms whereby IGOs may affect environmental performance in developing countries. The strong effect of umbrella organizations such as the EU or ASEAN, for example, is a first indication that some IGOs seem to be very successful in connecting different issues. Although environmental protection is usually not the main goal of these umbrella organizations, they often concern themselves with environmental issues also Different umbrella organizations such as the EU or ASEAN possess institutionalized committees or departments that deal exclusively with environmental protection. Hence, countries joining these IGOs for economic or political reasons are, as a side effect, also influenced with regard to their environmental quality.

This can be illustrated using the African Union (formerly the Organization of African Unity), an umbrella organization trying to promote greater unity and solidarity between African nations and to foster co-operation in different fields such as economic issues, human rights, etc. Among its institutional bodies, the organization has a Committee on Industry, Science and Technology, Energy, Natural Resources and Environment.Footnote 72 This committee has, for instance, a project on bio, safety jointly undertaken with the German technical co-operation agency (Deutsche Gesellschaft für Technische Zusammenarbeit GmbH) to provide the Union's member states with the necessary skills and technical tools to implement the Cartagena Protocol.Footnote 73

The effect of social IGOs in the case of SO₂ emissions seems to hint at two different mechanisms. On the one hand, these organizations appear to constitute a good forum for information dissemination, and through the socialization process that takes place at these fora they may also diffuse environmental protection, as proposed in the literature on policy diffusion.Footnote 74 On the other hand, many of these organizations – such as the WHO and ILO – or research related organizations – such as the International Commission for the Scientific Exploration of the Mediterranean Sea – often diffuse knowledge and technology helpful to the environment in general while aiming at improving or preserving human health, labour conditions or biodiversity.

Acknowledging the fact that 25 per cent of all diseases worldwide arise because of environmental hazards, the WHO carries out research and gives policy advice on how to deal with various forms of environmental hazards most effectively.Footnote 75 Among other things, the WHO offers guidelines on how to dispose of hazardous waste, documents the health risks associated with indoor air pollution, advocates measures to decrease indoor air pollution and monitors the changes in pollution levels in households around the world. These far-reaching measures make the organization an important diffuser of the latest research and knowledge on the impacts of various forms of environmental degradation and on effective countermeasures to tackle the different health problems associated with environmental pollution.

Technology and knowledge transfer as well as capacity building are also sometimes the tasks of nuclear and economic IGOs. For example, UNIDO (the UN Industrial Development Organization), which promotes industrial development mainly by providing technical co-operation, also has a special thematic focus on the environment and energy. In this context, UNIDO provides technical advice on topics such as cleaner production processes, renewable forms of energy and waste recycling.Footnote 76 Similarly, the IAEA supports developing countries with technical co-operation, besides providing information and technology on the safe use of nuclear energy and treatment of nuclear waste.Footnote 77 For example, the IAEA has carried out a project in Cameroon focusing on the use of nuclear techniques in groundwater assessment.Footnote 78

In contrast, the rather small impact of environmental organizations is somewhat surprising, since one would expect that IGOs that are established to deal with environmental issues would have a significant effect on pollution. This finding suggests that, although joining environmental IGOs commits countries to the idea of taking care of their environment, this does not have an impact on the way they act at the national level.Footnote 79

The lack of influence of environmental IGOs does have a methodological advantage as it allows us to address the problem of endogeneity. One potential risk of looking at IGO membership and its influence on environmental quality is that, at least concerning environmental IGOs, countries may ‘self-select’ into these IGOs. This would imply that only countries with a very good environmental record would join environmental IGOs because these countries can be sure of meeting the obligations prescribed by the respective organization. Yet, one could also argue that countries with larger environmental problems may be more willing to join environmental organizations, since these organizations could provide laggard countries with technology and know-how. Alternatively, polluting countries may join environmental organizations in order to signal to their citizenry that henceforward they are planning to take the environment more seriously. Since environmental IGOs are – if at all – only vaguely associated with CO₂ emissions, we can be rather confident that results are not due to self-selection into the organizations that do have an impact.

To provide further corroboration for the idea that technology and knowledge transfer as well as capacity building are indeed part of the influence of the different types of organizations, I have run the analysis on three different samples: all countries (i.e. including high-income countries), middle-income and low-income countries, and low-income countries only. If technology transfer is indeed one mechanism through which IGO membership influences the provision of environmental quality, we should observe that the effect of the various IGO memberships is stronger in the developing country sample than in the sample that also includes high-income countries. As the results in Table 4 show, the effect of umbrella, nuclear, military and general economic IGOs is weaker in samples including high-income countries than in the sample with low-income countries only. These findings thus reinforce the conclusion that membership in IGOs can be an opportunity for developing countries to obtain access to advanced technology and knowledge of how to combat environmental degradation.

Table 4

Disaggregating IGO Membership across Different Samples

Note: Panel-corrected standard errors in parentheses; ***p < 0.01, **p < 0.05, *p < 0.1. Country effects are not displayed in the regression table.

In addition to disaggregating IGO membership, I checked the robustness of my results using the different variables offered by the Correlates of War project.Footnote 80 The Correlates of War IGO dataset offers three slightly different variables measuring IGO membership. These measures differ according to whether a state has full, associated or observer membership. Up to now I have used the most inclusive (or least ‘stringent’) variable, the one that includes full, associated and observer membership. However, using either the most narrowly defined variable, which includes full membership only, or the IGO variable that includes both full and associated membership, while excluding observer status, instead of the most inclusive IGO variable, does not alter any of the earlier results. IGO membership, independent of its measurement, is always associated with a reduction in pollution (see columns 1 to 4 in Table 5).

Table 5

Robustness Checks

Note: Panel-corrected standard errors in parentheses; ***p < 0.01, **p < 0.05, *p < 0.1. Country effects are not displayed in the regression table

Moreover, although the test statistic for non-stationarity of panel data shows that all independent variables are stationary, each country's IGO membership usually increases over time. Therefore, it could be possible that the effect of IGO membership is merely due to this time trend and is not driven by IGO membership per se. To show that this is not the case, I created a variable that measures the deviation of each country's IGO membership from the average IGO membership per year. Positive deviations thus imply that this country is a member of more IGOs than the average country in this year whereas negative deviations imply that this country is a member of fewer IGOs than the average country. The results, as shown in columns 5 and 6 in Table 5, are the same as in the case of the general IGO variable: countries that are members of more than the average number of IGOs are better stewards of their environment.

Finally, the robustness of the results was further checked by replacing the Polity IV measure of democracy with the dichotomous ‘ACLP’ democracy variableFootnote 81 and Bueno de Mesquita et al.'s democracy indicator.Footnote 82

As the results in Table 6 show, replacing the measure of democracy does not change the results reported above. At the stage of early economic development, political regime type does not seem to affect environmental quality. As long as citizens do not strongly demand that their political leaders use the scarce resources available to reduce pollution, democracies seem to be no better stewards of their environment than their autocratic counterparts.

Table 6

Robustness Checks

Note: Panel-corrected standard errors in parentheses; ***p < 0.01, **p < 0.05, *p < 0.1.

Country effects are not displayed in the regression table.