İktisat Bölümü
https://hdl.handle.net/11491/2201
Department of Economics2024-03-29T12:46:57ZThe asymmetric effect of renewable and non-renewable energy on carbon emissions in OECD: new evidence from non-linear panel ARDL model
https://hdl.handle.net/11491/8772
The asymmetric effect of renewable and non-renewable energy on carbon emissions in OECD: new evidence from non-linear panel ARDL model
Şanlı, Devran; Muratoğlu, Yusuf; Songur, Mehmet; Uğurlu, Erginbay
The level of economic income, population density and sources of energy supply is critical in assessing environmental quality. Recent empirical studies paid limited attention to the role of renewable (RE) and fossil energy (NRE) supply in carbon pollution regarding the Environmental Kuznets Hypothesis (EKC). Therefore, this study investigates the asymmetric relationships between carbon emissions and energy sources on the one hand and the environmental Kuznets hypothesis on the other hand for OECD countries, comprising countries with significant renewable energy supplies. The study includes the annual data from 1990 to 2021 and performs panel non-linear ARDL regression. The empirical results clearly show that RE and NRE have asymmetric effects on emissions in the long run but not in the short run. Both positive and negative shocks in RE reduce CO2 emissions in OECD economies, while asymmetric shocks in NRE substantially increase them. Increasing RE supply is clearly effective in reducing emissions. However, unlike most previous studies, this study shows that RE does not significantly reduce CO2 emissions in OECD countries. The error correction term (ect.) in the NARDL model is negative and significant. The magnitude of the term indicates that the system will return to long-term equilibrium about 4.2 years after any shock. Furthermore, we show that the EKC Hypothesis is supported in OECD countries. The turning point of the EKC is at $4085.77 per capita. Besides, regression with Driscoll-Kraay standard errors and Augmented Mean Group (AMG) estimator approach were used for robustness checks. The findings from the robustness check are consistent with the NARDL findings. Policies based on the promotion of a lowcarbon and sustainable green environment should place greater emphasis on renewable resources even in OECD countries. Moreover, while many studies in the literature address asymmetric effects and EKC as energy consumption or utilisation, the novelty of this study is that it approaches the issue regarding energy supply with asymmetric effects for RE and NRE.
2023-01-01T00:00:00ZTürkiye’de Hisse Senedi Fiyatları İle Reel Döviz Kuru Arasındaki İlişki: Simetrik Ve Asimetrik Nedensellik Analizi
https://hdl.handle.net/11491/8318
Türkiye’de Hisse Senedi Fiyatları İle Reel Döviz Kuru Arasındaki İlişki: Simetrik Ve Asimetrik Nedensellik Analizi
Sertkaya, Burak; Songur, Mehmet
Küresel piyasaların her geçen gün daha global bir yapıya sahip olması, ülkelerin döviz kurları ve hisse senedi piyasaları üzerinde daha etkili olmaktadır. İzlenen her türlü politika döviz piyasalarına ve hisse senedi piyasalarına doğrudan yansımaktadır. Bu bakımdan her iki piyasada meydana gelen tepkiler ortaya konulan politikaların sonuçları bakımından önem teşkil eder. Hisse senedi piyasaları ile döviz kuru piyasalarında ortaya çıkacak herhangi bir politika değişimi, söz konusu iki piyasaya hızlı bir şekilde yansıyacaktır. Sermaye akımlarına oldukça duyarlı olan Türkiye gibi gelişmekte olan ülkelerde ise, döviz kurları ile hisse senedi piyasaları arasında yakın bir ilişki vardır. Bu çalışmada, Türkiye için hisse senedi fiyatları ile reel döviz kurları arasındaki ilişkinin varlığı farklı döviz kuru yaklaşımları çerçevesinde ampirik olarak analiz edilmiştir. Söz konusu ilişkinin varlığı 1996:2-2018:6 dönemi için aylık hisse senedi endeksi ve reel döviz kuru endeksi verileri kullanılarak ele alınmıştır. Çalışmadaki değişkenler arasındaki ilişki, nedensellik sonucuna bağlı olarak karşılaştırma imkânı sunması nedeniyle simetrik ve asimetrik nedensellik testleri ile analiz edilmiştir. Belirtilen ampirik analize göre, değişkenler arasındaki nedensellik ilişkisinin farklılaştığı gözlenmiştir. Simetrik analize göre, hisse senedi fiyatları reel döviz kuru endeksinin nedenidir. Asimetrik analize göre, pozitif bileşenlerde değişkenler arasında karşılıklı bir nedensellik ilişkisi vardır. Negatif bileşenlerde ise, değişkenler arasında karşılıklı nedensellik ilişkisi yoktur.; The fact that the global markets have a more global structure day by day is more effective on the exchange rates and stock markets of the countries. All kinds of policies followed directly reflect on foreign exchange markets and stock markets. In this respect, the reactions that occur in both markets are important in terms of the results of the policies put forward. Any change in the stock markets and exchange rate markets will be reflected in these two markets quickly. In developing countries such as Turkey which is highly sensitive to capital flows, there is a close relationship between exchange rates and stock markets. In this study, the presence of the relationship between stock prices and real exchange rates in Turkey were analyzed under different exchange rate empirical approaches. The existence of the mentioned relationship is examined by using monthly stock index and real exchange rate index data for the period 1996:2-2018:6. The relationship between the variables in the study was analyzed with symmetric and asymmetric causality tests because of the possibility of comparison based on the causality result. According to the empirical analysis, it was observed that the causality relationship between the variables varied. According to symmetric analysis, stock prices are the cause of the real exchange rate index. According to asymmetric analysis, there is a bilateral causality relationship between variables for positive components. In negative components, there is no bilateral causality relationship between variables.
2021-01-01T00:00:00ZA new explainable robust high-order intuitionistic fuzzy time-series method
https://hdl.handle.net/11491/7371
A new explainable robust high-order intuitionistic fuzzy time-series method
Koçak, Cem; Eğrioğlu, Erol; Baş, Eren
Fuzzy time series, based on type-1 fuzzy sets, continue to have a wide range of use in the literature. These methods use only membership values to determine the fuzzy relations. However, intuitionistic fuzzy time series models use both membership values and non-membership values. So it can be considered that the use of intuitionistic fuzzy time forecasting models will be able to increase the forecasting performance because the intuitionistic fuzzy sets have more information than fuzzy sets. Therefore, intuitionistic fuzzy time series models have started to employ for forecasting the real-life series in the fuzzy time series literature. A novel, explainable, robust high-order intuitionistic fuzzy time series forecasting method is proposed based on a newly defined model. In the proposed method, the intuitionistic fuzzy c-means algorithm is used for the fuzzification of observations, and a robust regression method employed for determining fuzzy relations. With the use of robust regression in determining the fuzzy relationships, all inputs of the proposed method can be explainable and they can be tested and commented on statistically. Applications of this study are made by using energy data of Primary Energy Consumption between the years 1965 and 2016 for 23 countries in the region of Europe-Eurasia. The forecasting performance of the proposed method is compared with the performance of some selected benchmarks, and the obtained results are discussed.
2021-01-01T00:00:00ZDecent work and economic growth as a sustainable development policy
https://hdl.handle.net/11491/6289
Decent work and economic growth as a sustainable development policy
Yıldırım, Ahmet Eren
[No abstract available]
2019-01-01T00:00:00Z