Browsing by Author "Ayhan, Fatih"

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Citation - WoS: 10
Citation - Scopus: 12
Asymmetric nexus of coal consumption with environmental quality and economic growth: Evidence from BRICS- E7- and Fragile Five countries by novel quantile approaches
(SAGE PUBLICATIONS LTD, 2024) Mustafa Tevfik Kartal; Hasan Murat Ertugrul; Dilvin Taskin; Fatih Ayhan; Taşkın, Dilvin; Ertuğrul, Hasan Murat; Ayhan, Fatih; Kartal, Mustafa Tevfik
The study analyzes the asymmetric nexus of coal consumption with environmental quality and economic growth. In this context the study focuses on eight leading emerging countries that take place in BRICS E7 and Fragile Five groups. Also the study uses yearly data from 1989 to 2021 and performs novel quantile methods such as Granger Causality-in-Quantiles and Quantile-on-Quantile Regression (QQR). Also quantile regression is used for robustness check. The results present that (i) there are causalities from coal consumption to both environmental quality and economic growth at 10% significance whereas quantile and country-based results differ, (ii) effects of coal consumption on environmental quality are much stronger in lower quantiles for Brazil Indonesia India South Africa and Turkey but in higher quantiles for China Mexico and Russia, (iii) effects of coal consumption on economic growth are much stronger in lower quantiles for Brazil Indonesia India Russia South Africa and Turkey, in higher quantiles for China, lower and middle quantiles for Russia, and all quantiles for Mexico, and (iv) the robustness of the QQR results are validated. Hence empirical outcomes underline the highly crucial effects of coal consumption on environmental quality and economic growth in the countries. The results imply that policymakers should focus on efforts to decrease coal consumption gradually by applying a macro transition plan to increase environmental quality without causing economic decline by considering changing effects of coal consumption at quantiles and countries.
Citation - WoS: 17
Citation - Scopus: 18
Efficiency of green bond- clean energy- oil price- and geopolitical risk on sectoral decarbonization: Evidence from the globe by daily data and marginal effect analysis
(ELSEVIER SCI LTD, 2025) Tevfik Kartal; Cosimo Magazzino; Dilvin Taskin; Ozer Depren; Fatih Ayhan; Taşkın, Dilvin; Depren, Özer; Magazzino, Cosimo; Ayhan, Fatih; Kartal, Mustafa Tevfik
The increasing global emphasis on environmental sustainability has amplified the strategic relevance of green finance and clean energy within decarbonization initiatives. In alignment with this paradigm the present study empirically investigates the impact of green bonds (GBs) and various subcategories of clean energy production (EP) while accounting for oil price dynamics and geopolitical risk (GPR) across the period from January 1 2019 to July 31 2024. The analysis employs the Kernel-Based Regularized Least Squares (KRLS) methodology to capture the marginal effects of these variables on sector-specific decarbonization outcomes. The empirical findings reveal several key insights: (i) neither GBs nor nuclear EP effectively contribute to sectoral decarbonization, (ii) hydro EP enhances decarbonization in the residential sector, (iii) solar EP significantly supports decarbonization in both the power generation and residential sectors, (iv) wind EP facilitates decarbonization particularly in the transportation and power sectors, (v) elevated oil prices and heightened geopolitical risk are associated with improved decarbonization outcomes in the industrial and power sectors, (vi) the KRLS model demonstrates a robust predictive capability achieving an accuracy rate of approximately 97 %, and (vii) the marginal effects of the independent variables are heterogeneous across sectors determinants and distributional percentiles. These results substantiate the argument that while GBs currently fall short in delivering effective decarbonization specific clean EP modalities alongside market and geopolitical conditions exert varied and sector-dependent influences. Thus the study offers critical empirical evidence to inform policymakers and investors regarding the nuanced role of green finance and clean EP in advancing global decarbonization agendas.
Citation - WoS: 35
Citation - Scopus: 42
How are energy transition and energy-related R&D investments effective in enabling decarbonization? Evidence from Nordic Countries by novel WLMC model
(Academic Press, 2024) Mustafa Tevfik Kartal; Muhammad Shahbaz; Dilvin Taşkın; Serpil Kılıç Depren; Fatih Ayhan; Taskin, Dilvin; Kılıç Depren, Serpil; Shahbaz, Muhammad; Depren, Serpil Kilic; Ayhan, Fatih; Kartal, Mustafa Tevfik
Public interest in climate change-related problems has been developing with the contribution of the recent energy crisis. Accordingly countries have been increasing their efforts to decarbonize economies. In this context energy transition and energy-related research and development (R&D) investments can be important strategic tools to be helpful to countries in the decarbonization of economies. Among all Nordic countries have come to the force because of their well-known position as green economies. Hence this study examines Nordic countries to investigate the impact of energy transition renewable energy R&D investments (RRD) energy efficiency R&D investments (EEF) on carbon dioxide (CO2) emissions by performing wavelet local multiple correlation (WLMC) model and using data from 2000/1 to 2021/12. The outcomes reveal that (i) based on bi-variate cases energy transition and RRD have a mixed impact on CO2 emissions in all countries across all frequencies, EEF has a declining impact on CO2 emissions in Norway (Sweden) at low and medium (very high) frequencies, (ii) according to four-variate cases all variables have a combined increasing impact on CO2 emissions, (iii) RRD is the most influential dominant factor in all countries excluding Norway where EEF is the pioneering one. Thus the reach proves the varying impacts of energy transition RRD and EEF investments on CO2 emissions. In line with the outcomes of the novel WLMC model various policy endeavors such as focusing on displacement between sub-types of R&D investments are argued to ensure the decarbonization of the economies. © 2024 Elsevier B.V. All rights reserved.
Citation - WoS: 6
Citation - Scopus: 7
Impact of productive capacity shifts- energy-related R&D investments- energy use- and income on environmental degradation: Evidence from leading developed countries
(PERGAMON-ELSEVIER SCIENCE LTD, 2025) Mustafa Tevfik Kartal; M. Santosh; Dilvin Taskn; Serpil Kilic Depren; Fatih Ayhan; Taşkın, Dilvin; Ayhan, Fatih; Kılıç Depren, Serpil; Taskn, Dilvin; Depren, Serpil Kilic; Santosh, M.; Kartal, Mustafa Tevfik
Environmental degradation (ED) has emerged as a significant challenge against the increasing demands of modern civilization. Therefore transforming the economic structure into an eco-friendly structure is highly critical. So this study focuses on the impacts of productive capacity shifts in key areas on ED in leading six developed economies by considering carbon dioxide (CO2) emissions as a dependent variable, using the productive capacity index (PCI) for human capital (PCI-HCA) transport (PCI-TRA) institutions (PCI-INS) energy-related public R&D investments economic growth nuclear energy and renewable energy as independent variables, and applies a kernel-based regularized least squares (KRLS) method on data from 2000 to 2022. The results show that (i) PCI-HCA curbs CO2 emissions in all countries except the United Kingdom, (ii) PCI-TRA and PCI-INS are ineffective in declining CO2 emissions in all countries), (iii) R&D investments are helpful in all countries except Canada and Japan, (iv) economic growth structure is not eco-friendly in all countries, (v) nuclear (renewable) energy use is beneficial in Japan (all countries except Canada & France, (vi) KRLS method provides high estimation results similar to 99.2 %. Accordingly the study discusses policy implications to prevent the ED by benefitting from productive capacity shifts clean energy and R&D investments in transforming economic structure.
Role of Market and Nonmarket-Based Environmental Policies, Energy Use, and Income on Environmental Sustainability: The Case of G7 Countries
(Elsevier, 2025) Gafarli, Galib; Taskin, Dilvin; Depren, Ozer; Ayhan, Fatih; Kartal, Mustafa Tevfik
Because the role of stringent environmental policies, energy use, and eco-friendly economic growth is highly critical in combating climate-related problems and preserving environmental quality, this study uncovers the incremental impact of aforementioned factors on load capacity factor (LCF) in G7 countries between 2000 and 2020 by performing a kernel-based regularized least squares (KRLS) model. The outcomes show that (i) gross domestic product (GDP) has only a supporting impact on LCF in the USA; (ii) market-based environmental policies are beneficial in Canada, France, Japan, and the USA; (iii) nonmarket-based environmental policies are helpful in France and USA; (iv) renewable energy use has positive support in Germany, Italy, Great Britain, and USA; (v) fossil energy use is harmful in all countries; (vi) the KRLS model has a high prediction performance; (vii) with regarding to G7 countries, the USA has the most positive condition. Thus, the study empirically highlights the average and pointwise incremental impact of the factors considered on LCF across countries and percentiles. Accordingly, the study discusses various policy options, such as mainly focusing on market-based environmental policies through making required regulations, considering also nonmarket-based environmental policies as a supportive mechanism, relying on further use of renewable energy through support packages and incentives, which should be taken into account in case of any additional measures application in the environmental area.