اثر آستانه‌ای سرمایه‌گذاری مستقیم خارجی بر شاخص عملکرد محیط‌زیست در کشورهای منطقه خاورمیانه و شمال آفریقا و عضو سازمان همکاری و توسعۀ اقتصادی (رهیافت انتقال ملایم در داده‌های تابلویی)

Extended Abstract
Introduction
Foreign direct investment (FDI), financial development, and social globalization represent three pivotal variables that can either degrade or enhance environmental quality through multiple, often countervailing channels. Theoretically, FDI exhibits a dualistic character: on one hand, the relocation of pollution-intensive industries to jurisdictions with weaker environmental standards may elevate emissions the so-called pollution haven effect; on the other hand, FDI can facilitate the transfer of clean technologies, enhance productive efficiency, and improve environmental management practices, thereby contributing positively to ecological outcomes. Financial development, contingent upon a country's institutional framework, may channel capital toward green investments and low-carbon innovations or, conversely, direct resources toward environmentally degrading sectors. Similarly, social globalization can intensify societal pressure for environmental compliance by fostering transnational communication, enabling the free flow of information, and heightening public environmental awareness. However, in certain contexts, it may exert countervailing pressures by promoting resource-intensive consumption patterns and stimulating demand for industrial goods.
A critical insight emerging from this analysis is that the environmental effects of these variables are neither uniform nor strictly linear across countries. Rather, their magnitude and even directional sign varies depending on contextual factors such as the level of economic development, institutional capacity, financial sector structure, and technological absorptive capacity. These nonlinear dynamics arise because the net impact of FDI, financial development, and social globalization on environmental performance is fundamentally mediated by institutional quality, the stringency of environmental regulations, and the capacity to assimilate and deploy clean technologies. Consequently, upon surpassing critical threshold levels of these moderating factors, the direction and intensity of their influence on environmental performance indices may undergo qualitative shifts. Specifically, an economic variable may exert a detrimental effect on environmental quality at early stages of development but, after crossing a certain threshold, generate improvements in ecological outcomes. Therefore, the presence of threshold effects and dynamic nonlinearities among these variables should be anticipated, and the examination of purely linear relationships risks yielding an incomplete and potentially misleading understanding of their complex environmental implications.
Objective
The primary objective of this study is to investigate the nonlinear and threshold-dependent effects of foreign direct investment (FDI), financial development, and social globalization on environmental performance across Middle Eastern and North African (MENA) and Organisation for Economic Co-operation and Development (OECD) countries. Specifically, the research aims to determine whether the impact of these variables on the Environmental Performance Index (EPI) varies across distinct FDI regimes and to compare both the directional sign and magnitude of these effects between developing and developed economies.
Research Method
This study employs a quantitative applied research design utilizing an unbalanced panel dataset comprising 59 countries of 22 Middle Eastern and North African (MENA) nations and 37 Organisation for Economic Co-operation and Development (OECD) member states, spanning the period 1995–2023. Environmental performance is operationalized using the Environmental Performance Index (EPI), published annually by the Yale Center for Environmental Law & Policy. Data on foreign direct investment (FDI), financial development, and GDP per capita are sourced from the World Bank's World Development Indicators database, while social globalization is proxied by the social dimension of the KOF Globalisation Index. To control for cross-country variations in economic development, GDP per capita (constant 2015 US dollars) is incorporated as a covariate.
To capture nonlinear dynamics, gradual regime transitions, and heterogeneous effects across countries, the study implements the panel smooth transition regression (PSTR) methodology. FDI is selected as the transition (threshold) variable based on its theoretical relevance to environmental outcomes and empirical validation through specification tests. This approach permits slope coefficients to vary smoothly across regimes as a function of the transition variable, while simultaneously controlling for unobserved country-specific heterogeneity and temporal dependencies through fixed effects and lagged dependent variable specifications.
Results and Discussion
The empirical findings provide robust evidence of nonlinear and threshold-dependent effects in the relationship between economic globalization and environmental performance. In Middle Eastern and North African (MENA) countries, foreign direct investment (FDI) exerts a negative influence on environmental performance at lower intensity levels, reflecting the predominance of pollution-intensive activities and relatively weak environmental regulatory frameworks during the initial phases of FDI inflows. However, once FDI surpasses a critical threshold, its impact reverses and becomes positive, signaling the emergence of green spillover effects transmitted through the adoption of cleaner technologies, enhanced production standards, and improved environmental management practices.
In contrast, in Organisation for Economic Co-operation and Development (OECD) countries, FDI initially contributes positively or at minimum, neutrally to environmental performance. Yet beyond a certain threshold level, further increases in FDI intensify environmental pressures and precipitate a deterioration in Environmental Performance Index (EPI) scores. Financial development and social globalization similarly exhibit regime-dependent effects, underscoring the pivotal role of institutional quality, regulatory stringency, and policy coherence in mediating environmental outcomes. Collectively, these results reconcile competing theoretical perspectives by demonstrating that pollution haven and pollution halo effects may coexist within a unified analytical framework, with their relative dominance contingent upon FDI intensity levels and countries' developmental stages.
Conclusion
This study concludes that the effects of foreign direct investment (FDI), financial development, and social globalization on environmental performance are inherently nonlinear and threshold-dependent. The directional sign and magnitude of these effects diverge markedly between Middle Eastern and North African (MENA) and Organisation for Economic Co-operation and Development (OECD) countries, underscoring the critical mediating role of institutional capacity, regulatory quality, and developmental stage. Collectively, the findings demonstrate that the environmental consequences of economic and social integration are contingent upon countries' developmental trajectories and institutional endowments. Consequently, neglecting threshold dynamics in empirical modeling risks generating erroneous policy prescriptions that fail to account for regime-dependent effects.
Accordingly, policymakers should adopt differentiated, context-sensitive strategies that actively channel foreign investment toward environmentally sustainable sectors while simultaneously strengthening financial governance frameworks and institutional capacities. Such an integrated approach can harness the potential of globalization to advance ecological objectives, rather than inadvertently exacerbating environmental degradation through one-size-fits-all policy designs.