Co2 Emisyonlarını Etkileyen Faktörlerin Zamanla Değişen Katsayılı Parametrik Olmayan Panel Veri Modelleri ile Analizi

Öz

İklim değişikliğinin, küresel ısınmanın ve çevresel bozulmanın bir nedeni olarak karbondioksit (CO2) emisyonlarından oluşan sera gazları gösterilmektedir. CO2 yeryüzüne insan faaliyetleri nedeniyle yayılarak genellikle çevreye zarar verir ve iklim değişikliğine veya küresel ısınmaya yol açar. Bu sebeple CO2 emisyonlarını etkileyen ekonomik ve ekonomik olmayan birçok sosyal faktör araştırmalara konu olmuştur. Ancak çoğu araştırmada CO2 emisyonları konusunda hem ekonomik büyüme hem de enerji kullanımı gibi ana faktörleri de etkileyen ekonomik belirsizlik dikkate alınmamıştır. Bu çalışmada kişi başına düşen CO2 emisyonları ve başta ekonomik belirsizlik (dünya belirsizlik indeksi ile ölçülen) olmak üzere diğer değişkenler arasındaki ilişki ele alınmıştır. 14 OECD ülkesinin 2000-2021 yılları arasındaki verileri zamanla değişen katsayılı parametrik olmayan panel veri modeliyle incelenmiştir. Trend fonksiyonları ve parametrik olmayan katsayı fonksiyonları tahmin edilerek doğrusal olmayan sonuçlara ulaşılmıştır. Parametrik olmayan katsayı fonksiyonlarının CO2 emisyonları üzerinde etkisi zaman içerisinde değişiklik göstermektedir. Sonuçlarımıza göre ele alınan dönem boyunca ekonomik belirsizlik ile CO2 emisyonları arasında ters yönlü bir ilişki bulunmaktadır ve zaman içerisinde düşüş eğiliminde devam etmektedir. Kişi başına düşen GSYH, nüfus ve yenilenebilir enerjinin parametrik olmayan katsayıları zaman içerisinde negatif ve pozitif olarak değişmektedir. Ticaret 2000’li yıllarında başında anlamsız bir değişken olmasına rağmen 2009-2013 yılları arasında anlamlı bir değişkendir, ancak 2021 yılında etkisi tekrar anlamsızlaşmıştır.

Anahtar Kelimeler

• Parametrik olmayan panel veri
• zamanla değişen katsayı fonksiyonları
• CO2 Emisyonları

Analyzing the Factors Affecting CO2 Emissions Using Nonparametric Time Varying Coefficient Panel Data Models

Öz

Carbon dioxide (CO2) emissions and other greenhouse gases are one of the reasons for climate change, global warming, and environmental degradation. CO2 is distributed throughout the Earth’s surface by human activity and is often harmful to the environment by causing climate change (i.e., global warming). Therefore, the literature has examined many economic and noneconomic social factors that affect CO2 emissions. However, most studies, have ignored the economic uncertainty regarding CO2 emissions effects on main factors such as economic growth and energy use. This study, discusses the relationships per capita CO2 emissions has with other variables, especially economic uncertainty as measured by the World Uncertainty Index. This article examines the relationship by utilizing the data for 14 OECD countries between 2000-2021 using a non-parametric panel data model with time-varying coefficients. By estimating trend functions and nonparametric coefficient functions, the study’s results show nonparametric coefficient functions on CO2 emissions to vary with time. In terms of signs and significance, the nonparametric coefficient function for economic uncertainty had a significant negative effect over the 2000-2021 period. In addition, economic uncertainty sustained a negative impact over time. The signs for nonparametric coefficients regarding GDP per capita, population, and renewable energy were seen to fluctuate, alternating between negative and positive values over time. Although trade was insignificant during the early 2000s, it became a significant variable between 2009-2013, while having no significant sustained effect in 2021.

Anahtar Kelimeler

• nonparametric panel data
• time-varying coefficient function
• CO2 emissions

Kaynakça

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