Analyzing the Environmental Kuznets Curve Hypothesis in Terms of Economic Growth and Different Types of Globalization in Türkiye
Melike Atay Polat, Suzan ErgünEnvironmental pollution has become one of the issues most widely discussed by researchers, scientists, and policy makers these days. In particular, investigating the determinants of CO2 emissions is one of the leading areas of interest for scientists . Meanwhile, globalization causes countries to interact with each other economically, politically, and socially, and this interaction inevitably affects the environment. Therefore, globalization is an important determinant of CO2 emissions. This study aims to evaluate the dynamic effects different types of globalization (economic, social, and political) have on environmental quality in Türkiye with reference to the environmental Kuznets curve hypothesis during the 1970-2018 period using the vector error correction model (VECM). The presence of a long-term relationship among CO2 emissions per capita, GDP per capita, economic globalization, social globalization, and political globalization for Türkiye has been demonstrated using the Johansen cointegration test. According to the results, the VECM Granger causality test has determined a short-term one-way causality nexus from economic globalization to CO2 emissions and from social globalization to political globalization. In terms of long-term estimators, the study has concluded GDP per capita, economic globalization, and social globalization to significantly and positively affect CO2 emissions per capita and the square of GDP per capita and political globalization to negatively affect CO2 emissions per capita at a significant level..
Türkiye’de Çevresel Kuznets Eğrisi Hipotezinin Ekonomik Büyüme ve Farklı Küreselleşme Türleri Bakımından Analizi
Melike Atay Polat, Suzan ErgünÇevre kirliliği günümüzde araştırmacılar, bilim adamları ve politika yapıcılar tarafından geniş çapta üzerinde en fazla durulan konulardan biri haline gelmiştir. Özellikle CO2 salınımının belirleyicilerini araştırmak bilim adamları için önde gelen ilgi alanlarından biridir. Diğer yandan küreselleşme, ülkelerin ekonomik, politik ve sosyal yönlerden birbirleriyle etkileşime geçmesine neden olur ve kaçınılmaz olarak bu etkileşimden çevre etkilenir. Bu nedenle küreselleşme CO2 emisyonlarının önemli bir belirleyicisidir. Bu çalışma, 1970-2018 döneminde Türkiye’de Çevresel Kuznets Eğrisi hipotezinden hareketle farklı küreselleşme türlerinin (ekonomik, sosyal ve politik) çevre kalitesi üzerindeki dinamik etkilerini Vektör Hata Düzeltme Modeli (VECM) ile değerlendirmeyi amaçlamıştır. Türkiye için kişi başı CO2 emisyonu, kişi başı GSYH, ekonomik küreselleşme, sosyal küreselleşme ve politik küreselleşme arasında uzun dönem ilişkinin varlığı Johansen eşbütünleşme testi ile ortaya konmuştur. VECM Granger nedensellik testi sonuçlarına göre kısa dönemde ekonomik küreselleşmeden CO2 emisyonuna ve sosyal küreselleşmeden politik küreselleşmeye doğru tek yönlü nedensellik ilişkisi tespit edilmiştir. Ayrıca, uzun dönem tahmincileri bakımından kişi başı GSYH, ekonomik ve sosyal küreselleşmenin kişi başı CO2 emisyonunu pozitif yönde etkilediği, buna karşılık kişi başı GSYH’nın karesi ve politik küreselleşmenin kişi başı CO2 emisyonunu negatif yönde ve anlamlı olarak etkilediği sonucuna ulaşılmıştır. Bulgular, Türkiye’de politika yapıcıların çevresel kaliteyi iyileştirmesi için iklim değişikliği politikalarını belirlerken ve uygularken farklı küreselleşme türlerini de dikkate almaları gerektiğini göstermektedir.
Environmental pollution is an important problem threatening the world, and countries have implemented environmentally friendly policies in order to improve environmental quality and sustain economic growth. However, globalization, which expresses the economic, social, and political integration of countries, is an important factor in terms of environmental quality, especially with regard to CO2 emissions, because globalization increases countries’ interactions with each other economically, socially, and politically, and the interactions between different countries inevitably affect CO2 emissions. Globalization can affect environmental quality in two ways. Firstly, globalization can improve environmental quality by reducing CO2 emissions. Secondly, globalization can harm environmental quality by increasing CO2 emissions. Therefore, determining the nexus between globalization and environmental quality can help both governments and policy makers regulate their environmental policies.
This study investigates the relationship between economic growth and different types of globalization (e.g., economic, social, political) within the framework of the environmental Kuznets curve (EKC) hypothesis for the period of 1970-2018 in Türkiye. Previous papers have addressed the general globalization index and investigated its effect on environmental quality (Acheampong et al., 2019; Chishti et al., 2020; Sheraz et al., 2021; Yang et al., 2021). Based on the EKC hypothesis, this paper differentiates itself from others by analyzing the impacts different types of globalization (e.g., economic, social, political) have on environmental quality for Türkiye within the scope of the vector error correction model (VECM).
In order to analyze the nexus of the variables, the study first conducted a stationarity test for the series using the augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) tests. The long-term relationships among the variables were investigated using the Johansen cointegration test, then the long-term coefficients were determined using fully modified ordinary least square (FMOLS) and dynamic ordinary least square (DOLS) estimators. Afterward, the short- and longterm causality nexus was analyzed using the VECM Granger causality test. Lastly, variance decomposition and impulse-response functions were used to examine the effects of shocks.
According to the findings from the ADF and PP unit root tests, the variables of CO2 emissions per capita, GDP per capita, economic globalization, social globalization, and political globalization were found to be stationary at the first difference. Johansen cointegration test findings indicate that long-term relationships exist among CO2 emissions per capita, GDP per capita, economic globalization, social globalization, and political globalization in Türkiye. According to the findings from the VECM Granger causality test, short-term one-way causality nexuses occur from economic globalization to CO2 emissions and from social globalization to political globalization. In addition, the negative sign and statistical significance of the error correction coefficient reveal the presence of long-term causality nexuses from economic globalization, social globalization, and political globalization to CO2 emissions. After determining the presence of longterm relationships among the variables, the long-term coefficients were estimated using the FMOLS and DOLS estimators. The long-term estimators reveal CO2 emissions per capita to be significantly and positively affected by GDP per capita, economic globalization, and social globalization, while being significantly and negatively affected by the square of GDP per capita and political globalization. In addition, the results from the relevant tests have revealed evidence for the validity of the EKC hypothesis in Türkiye. Lastly, the study also performed impulse response functions and a variance decomposition analysis. According to the impulse response functions, per capita CO2 emissions reacted positively in the fourth period to a shock of one standard deviation in per capita GDP before stagnating. While per capita CO2 emissions react positively to a shock to the standard deviation as seen in economic globalization in the second period, per capita CO2 emissions had reacted positively to a standard deviation shock, as seen in social globalization and political globalization in the first period. The variance decomposition approach shows a change in CO2 emissions per capita to have mostly been self-caused, followed by economic globalization, political globalization, GDP per capita, and social globalization, respectively. In other words, while 56.73% of the one-unit change in CO2 emissions per capita in the tenth period is self-explained, the contributions from economic growth, economic globalization, social globalization, and political globalization toward CO2 emissions for the tenth period were 4.78%, 30%, 0.93%, and 7.45%, respectively.
The findings reveal the various types of globalization (e.g., economic, social, political) to affect environmental degradation differently. In this context, environmental policies should be designed by considering how each type of globalization affects environmental quality. In addition, policies need to be implemented to reduce environmental pollution without reducing the growth rate.
