Browsing by Author "Kartal, Mustafa Tevfik"

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Analysis of disaggregated level energy use income geopolitical risk energy transition and energy price impact on decarbonization of main sectors in BRICS countries by marginal analysis
(SAGE Publications Inc., 2025) Mustafa Tevfik Kartal; Dilvin Taşkın; Serpil Kılıç Depren; Piotr F. Borowski; Mert Sarioglu; Taskin, Dilvin; Sarioglu, Mert; Kılıç Depren, Serpil; Depren, Serpil Kilic; Kartal, Mustafa Tevfik; Borowski, Piotr F.
This study analyzes the impact of critical factors (i.e. energy consumption (EC) income (GDP) geopolitical risk (GPR) energy transition and energy prices). In doing this the study focuses on Brazil Russia India China and South Africa (BRICS) countries which are the leading emerging countries considers carbon dioxide (CO2) emissions industry power and transport sectors uses yearly data from 2000 to 2022 and performs a kernel-based regularized least squares (KRLS) approach to uncover the marginal impact of the factors. The outcomes demonstrate that (a) the impacts of the factors on sectoral CO2emissions vary marginally across economic sectors factors used and levels of the variables, (b) the statistical significance of the factors considered differentiate which implies that some factors are much more critical than others across countries and sectors, (c) for industry sector CO2emissions Brazil can benefit from the marginal decreasing impact of gas and renewable EC GDP and GPR whereas it is valid in Russia (South Africa) for gas (GPR and energy prices) impact, (d) for power sector CO2emissions Brazil can use nuclear EC energy transition and energy prices whereas nuclear and renewable EC as well as GDP and GPR (renewable EC and GPR) is beneficial for Russia (South Africa), (e) for transport sector CO2emissions GPR (renewable EC) can be relied on in Brazil (Russia), and (f) the KRLS approach has a superior prediction capacity reaching 99.8%. Overall the study empirically shows the varying marginal impacts of the factors on the decarbonization of the sectors. © 2025 Elsevier B.V. All rights reserved.
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: 20
Citation - Scopus: 20
Dynamic relationship between green bonds- energy prices- geopolitical risk- and disaggregated level CO2 emissions: evidence from the globe by novel WLMC approach
(SPRINGER, 2024) Mustafa Tevfik Kartal; Dilvin Taskin; Serpil Kilic Depren; Taskin, Dilvin; Kılıç Depren, Serpil; Depren, Serpil Kilic; Kartal, Mustafa Tevfik
This research analyzes the dynamic relationship between green bonds energy prices geopolitical risk and CO2 emissions. In doing so the study examines the global scale at disaggregated (i.e. sectoral) level applies a novel time and frequency-based approach (i.e. wavelet local multiple correlation-WLMC) and uses high-frequency daily data between 1st January 2020 and 28th April 2023. In doing so the study considers the potential differences among sectors. So aggregated and disaggregated level CO2 emissions on sectoral bases are investigated. Hence the study comprehensively uncovers the effect of the aforementioned indicators on global CO2 emissions. The results reveal that on CO2 emissions (i) the most influential factor is the geopolitical risk (2020/1-2021/5) green bonds (2021/5-2021/7) energy prices (2021/7-2023/1) and green bonds (2023/1-2023/4), (ii) the effects of the influential factors are much weaker (stronger) at lower (higher) frequencies, (iii) the effect of the influential factors change based on times and frequencies, (iv) however the effects of the influential factors on CO2 emissions do not differ at aggregated or disaggregated levels. Overall the results present novel insights for time and frequency-varying effects as well as both aggregated and disaggregated level analyses of global CO(2 )emissions.
Citation - WoS: 2
Citation - Scopus: 1
Effect of AI-Related Patents, Energy Transition, Environmental Policy Stringency, Income, and Energy Consumption Sub-Types on the Environmental Sustainability: Evidence from China by KRLS Approach
(Academic Press Ltd- Elsevier Science Ltd, 2025) Taşkın, Dilvin; Kim, Eonsoo; Mukhtarov, Shahriyar; Kirikkaleli, Derviş; Kılıç Depren, Serpil; Park, Jinsu; Depren, Serpil Kilic; Kartal, Mustafa Tevfik
Due to the increasing negative effects on humanity, searching for potential solutions to combat environmental problems has been developing. Accordingly, the study examines the effect of a set of critical factors on environmental sustainability (ES) proxied by ecological footprint (EFP) and load capacity factor (LCF) in China. In this context, the study considers AI-related patents, energy transition, environmental policy stringency (EPS), income, and energy consumption (EC) sub-types and applies the Kernel Regularized Least Squares (KRLS) approach on data from 2000 to 2020 within the context of marginal effect analysis. The outcomes show that (i) AI-related patents and energy transition are completely ineffective to ensure ES; (ii) EPS are marginally effective only at 0.25th and 0.75th percentiles to support ES; (iii) economic growth as well as oil, gas, and coal EC are not good for ES across all percentiles; (iv) nuclear EC is only helpful at 0.25th percentiles, whereas renewable EC is completely unbeneficial; (v) KRLS approach presents successful prediction outcomes around 99.7 % (vi) some variables (i.e., nuclear and renewable EC as well as EPS); have marginal and varying effects across percentiles, whereas some others have not. Thus, the study empirically demonstrates the inefficiency of AI-related patents and energy transition on the ES, whereas EPS and nuclear EC can be helpful to develop ES in the Chinese case.
Citation - WoS: 5
Citation - Scopus: 5
Effect of energy transition R&D investments in energy income and energy use on the environment: Evidence from advanced countries by KRLS method
(Elsevier Ltd, 2025) Mustafa Tevfik Kartal; Dilvin Taşkın; Mubariz Mammadli; Cosimo Magazzino; Taşkın, Dilvin; Magazzino, Cosimo; Mammadli, Mübariz; Kartal, Mustafa Tevfik
Countries have been concerned about the energy transition and related research and development (R&D) investments in energy to combat environmental degradation due to their beneficial effects on energy use as a critical factor in environmental change. Accordingly the study uncovers the marginal effects of the energy transition renewable and nuclear energy R&D investments income and energy use on carbon dioxide emissions (ecological footprint for robustness) in six advanced countries by using data from 2000 to 2022 and performing the Kernel-based Least Squares method which provides marginal effect across percentiles. The results show that energy transition only develops the environment in France. Moreover R&D investments in renewable (nuclear) energy are beneficial for the environment in France and the UK (the US and the UK). Moreover income is helpful in most countries except Japan and the UK. On the other hand energy use is harmful in all countries. Thus the results present the beneficial effect of R&D investments in energy and the less helpful effect of the energy transition. Thus France the UK and the US have a better position to benefit from the energy transition and energy-related R&D investments. © 2025 Elsevier B.V. All rights reserved.
Citation - WoS: 31
Citation - Scopus: 42
Effects of Environment Social and Governance (ESG)disclosures on ESGscores: Investigating therole ofcorporategovernance forpubliclytraded Turkishcompanies
(Academic Press, 2024) Mustafa Tevfik Kartal; Dilvin Taşkın; Muhammad Shahbaz; Serpil Kılıç Depren; Ugur Korkut Pata; Taşkın, Dilvin; Korkut Pata, Ugur; Pata, Ugur Korkut; Kılıç Depren, Serpil; Shahbaz, Muhammad; Depren, Serpil Kilic; Kartal, Mustafa Tevfik
The world has experienced climate-related issues which increase the importance of ESG disclosures and corporate governance (CG) of companies which take place at the heart of economies. Therefore improving ESG disclosures and CG practices becomes significant to combat climate change at the company level. Considering that Türkiye restructured ESG disclosures in 2022 this study investigates the role of CG on the nexus between ESG scores of publicly traded companies (PTC) and ESG reports. So the study analyzes 102 PTC (full sample) 51 PTC in Borsa Istanbul Corporate Governance Index (in-sample) and the remaining 51 PTC (out-sample) using ESG disclosures of 2022 and applying novel super learner (SL) algorithm. Our results show that (i) SL has a higher prediction performance reaching ∼94.3%, (ii) the environment (governance) layer has the highest (lowest) total relative importance (contribution) to ESG scores in all samples, (iii) C8 S6 and E5 are the most important ESG principles in the full sample in-sample and out-sample respectively, (iv) the contribution of each ESG principles to the total ESG scores varies by sample, (v) CG plays a smoothing role for the relative importance of each ESG principle while the relative importance in the out-sample shows much higher volatility. Overall the study reveals the non-linear contributions of ESG principles on ESG scores and suggests that PTC should prioritize highly important ESG principles consider the moderating role of CG on the link between ESG scores and ESG disclosures and use ESG disclosures as a strategic tool to develop ESG scores and disclosures. © 2024 Elsevier B.V. All rights reserved.
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: 4
Citation - Scopus: 4
How are electricity generation effective on carbon neutrality in the global south? Evidence from sectoral CO2 emissions by daily data
(Elsevier B.V., 2024) Mustafa Tevfik Kartal; Ugur Korkut Pata; Dilvin Taşkın; Taşkın, Dilvin; Pata, Ugur Korkut; Kartal, Mustafa Tevfik
In light of the efforts to ensure carbon neutrality by combating climate-related problems the study investigates the effectiveness of electricity generation (EG) from the main renewable sources (hydro-HEG solar-SEG and wind-WEG). In this context the study examines the countries of the Global South (i.e. Brazil China and India) considers EG at a disaggregated level and sectoral CO2 emissions applies nonlinear methods and uses daily data between January 2 2019 and December 31 2022. The results demonstrate that (i) disaggregated EG sources have a stronger (weaker) time and frequency dependency on sectoral CO2 emissions in China (Brazil and India), (ii) HEG has a stimulating impact on sectoral CO2 emissions in all countries, (iii) SEG has an increasing impact on sectoral CO2 emissions in Brazil and China while it provides a decrease in sectoral CO2 emissions in India, (iv) WEG upsurges sectoral CO2 emissions in China while it achieves a CO2 reduction in Brazil and India, (v) disaggregated level EG has a causal impact on sectoral CO2 emissions across all quantiles except some lower middle and higher quantiles. The study adds scientific value to existing knowledge by analyzing for the first time which EG sources are effective in reducing daily CO2 emissions in the Global South. Based on the outcomes the study demonstrates that WEG is the best EG source for Brazil that SEG and WEG are optimal EG sources for India and that China cannot benefit from the EG sources considered. In this way the study provides fresh insights for the countries of the Global South and underlines the crucial role of renewable EG in ensuring carbon neutrality. © 2024 Elsevier B.V. All rights reserved.
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 - Scopus: 1
Impact of disaggregated level clean electricity on CO2 emissions: Evidence from EU-5 countries by bivariate and multivariate QQ approaches
(SAGE PUBLICATIONS LTD, 2024) Tevfik Kartal; Ugur Korkut Pata; Dilvin Taskin; Shahriyar Mukhtarov; Taşkın, Dilvin; Mukhtarov, Shahriyar; Pata, Ugur Korkut; Kartal, Mustafa Tevfik
Considering the energy crisis in Europe and searching for alternatives this study investigates the impact of clean electricity generation (EG) types on the environment. So the study focuses on EU-5 countries (Germany-DEU Spain-ESP France-FRA United Kingdom-GBR and Italy-ITA) uses CO2 emissions as environmental indicator and considers clean EG types as explanatory variables by controlling geopolitical risk. Accordingly the study uses data from 2(nd) January 2019 to 29(th) February 2024 and applies bivariate and multivariate quantile-on-quantile regression (BQQ & MQQ) and Granger causality-in-quantiles (GCQ) as the fundamental approaches while quantile regression (QR) is performed for the consistency check. The outcomes reveal that (i) hydro EG increases CO2 emissions across countries excluding DEU at lower and middle quantiles, (ii) solar EG curbs CO2 emissions at middle quantiles in DEU higher quantiles in ESP and FRA and middle and higher quantiles in ITA, (iii) wind EG has an almost decreasing impact across quantiles excluding higher quantiles in DEU and FRA, (iv) clean EG types are almost causally impactful on CO2 emissions across quantiles, (v) geopolitical risk decreases the power of the impact of clean EG alternatives on CO2 emissions but does not change them in a reverse way. To sum up the impact of clean EG types on CO2 emissions in EU-5 countries varies across EG types quantiles and countries. Thus the study suggests that wind EG is highly beneficial for all EU-5 countries while there is also room for growth to benefit from hydro and solar EG for some countries.
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.
Impact of Supply Chain Logistics and Green Transportation on Green Economics under Green Finance, Oil Price Shocks, and Geopolitical Risk: Evidence from the Globe via Novel Quantile Methods
(Springer, 2026) Taşkın, Dilvin; Kartal, Mustafa Tevfik
Countries' and societies' interest in becoming green has been developing in almost every area. Accordingly, the recent focus point has been becoming green economics. Therefore, dealing with green economics is important because it implicitly includes many issues. Therefore, to be compatible with the developing interest and importance of green economics, this study empirically examines green economics. In doing so, the study analyzes the global condition; uses the Nasdaq Green Economy Index (GREC) as the proxy of green economics; considers the Factset Supply Chain Logistics Index (SCLI) and Nasdaq Green Transportation Index (GTRI) as explanatory variables, which represent the critical factors in becoming green economics; controls the S&P Green Bond Index (SPGB), Brent Crude Oil Price (OIL), and geopolitical risk (GPR) index; uses data between 2nd January 2017 and 31st May 2024; and applies novel nonlinear quantile methods. The study shows that (i) SCLI and GTRI have a strong and increasing impact on GREC, where the power of increasing impact varies across quantiles; (ii) SCLI has a greater increasing impact than GTRI does on GREC; (iii) the impact of SCLI and GTRI on GREC continues to increase under the moderating impact of SPGB, OIL, and GPR, whereas these factors cause slight weakening; (iv) there is strong bidirectional causality; and (v) the robustness of the outcomes is verified by the alternative method. In this way, the empirical outcomes highlight the key role of supply chain logistics and green transportation in ensuring green economics even under the impact of green finance, oil prices, and geopolitical risk. Thus, in terms of outcomes, this study discusses policy endeavors (e.g., digitalization of supply chain logistics and electrification of transportation) to benefit from these factors to ensure further greening of the global economy.
Citation - WoS: 12
Citation - Scopus: 11
Interrelationship between environmental degradation- geopolitical risk- crude oil prices- and green bonds: Evidence from the globe by sectoral analysis
(ELSEVIER, 2024) Tevfik Kartal; Dilvin Taskin; Serpil Kilic Depren; Taşkın, Dilvin; Kılıç Depren, Serpil; Depren, Serpil Kilic; Kartal, Mustafa Tevfik
By considering the motion of the world is our home this study investigates the interrelationship between environmental degradation geopolitical risk crude oil prices and green bonds across the globe. So the research considers the probable differences between the sectors by making a detailed analysis of CO 2 emissions across sectors applies the novel WLMC method and uses daily data from 2nd January 2020 through 30th November 2023 for a time and frequency -based empirical analysis. The outcomes present that (i) the geopolitical risk is the most important variable on CO 2 emissions between 2020/1 and 2021/11 followed by Brent oil prices for the period 2021/12-2023/10, (ii) green bonds are highly effective on CO 2 emissions only around 2023/11, (iii) the impacts of the variables are quite weaker (stronger) at lower (higher) frequencies, (iv) the impacts of the variables are the same at aggregated and disaggregated levels, (v) the impact of the variables on CO 2 emissions change based on times and frequencies. Thus the outcomes demonstrate new insights for differentiating impacts across times and frequencies whereas the direction of the impacts is the same across aggregated and disaggregated levels. (c) 2024 International Association for Gondwana Research. Published by Elsevier B.V. All rights are reserved including those for text and data mining AI training and similar technologies.
Citation - WoS: 20
Citation - Scopus: 22
Modeling the link between environmental- social- and governance disclosures and scores: the case of publicly traded companies in the Borsa Istanbul Sustainability Index
(SPRINGER, 2024) Mustafa Tevfik Kartal; Serpil Kilic Depren; Ugur Korkut Pata; Dilvin Taskin; Tuba Savli; Taşkın, Dilvin; Kılıç Depren, Serpil; Pata, Ugur Korkut; Şavlı, Tuba; Depren, Serpil Kilic; Kartal, Mustafa Tevfik
This study constructs a proposed model to investigate the link between environmental social and governance (ESG) disclosures and ESG scores for publicly traded companies in the Borsa Istanbul Sustainability (XUSRD) index. In this context this study considers 66 companies examining recently structured ESG disclosures for 2022 that were published for the first time as novel data and applying a multilayer perceptron (MLP) artificial neural network algorithm. The relevant results are fourfold. (1) The MLP algorithm has explanatory power (i.e. R2) of 79% in estimating companies' ESG scores. (2) Common environment social and governance pillars have respective weights of 21.04% 44.87% 30.34% and 3.74% in total ESG scores. (3) The absolute and relative significance of each ESG reporting principle for companies' ESG scores varies. (4) According to absolute and relative significance the most effective ESG principle is the common principle followed by social and environmental principles whereas governance principles have less significance. Overall the results demonstrate that applying a linear approach to complete deficient ESG disclosures is inefficient for increasing companies' ESG scores, instead companies should focus on the ESG principles that have the highest relative significance. The findings of this study contribute to the literature by defining the most significant ESG principles for stimulating the ESG scores of companies in the XUSRD index.
Citation - WoS: 1
Citation - Scopus: 1
Relationship between CO2 Emissions and Energy Consumption Sub-Types under Impact of AI-Related Patents and Energy-Related R&D Investments: Evidence from the USA by Novel Quantile-Based Methods
(Elsevier Sci Ltd, 2026) Taşkın, Dilvin; Kim, Eonsoo; Mukhtarov, Shahriyar; Kirikkaleli, Derviş; Kılıç Depren, Serpil; Park, Jinsu; Depren, Serpil Kilic; Kartal, Mustafa Tevfik
The importance of AI and R&D investments has become increasingly salient in the context of rising carbon dioxide (CO2) emissions. So, this study examines how CO2 emissions relate to energy consumption (EC) sub-types and whether AI-related patents (AIP) and energy-related R&D investments (ERD) moderate the relationship. In this vein, the study focuses on the USA, uses EC sub-types as explanatory variables, considers the moderating role of AIP and ERD, and applies novel quantile-based methods on data from 1981/Q2 to 2020/Q4. The results indicate that (i) oil and coal EC are associated with higher CO2 emissions across quantiles in both bivariate and multivariate models; (ii) while gas EC increases CO2 emissions across all quantiles in bivariate and multivariate cases, there is a decreasing impact at lower quantiles with ERD moderation; (iii) nuclear EC increases CO2 emissions across all quantiles in bivariate case, whereas the impact changes under the moderating impacts of AIP and ERD; (iv) renewable EC decreases CO2 emissions across all quantiles in bivariate case, while the reducing impact is almost same under the moderating impacts of AIP and ERD; (v) AIP has a much stronger moderating impact than ERD on relationship between CO2 emissions and EC sub-types; (vi) there are generally causal impacts across quantiles, except for some lower, middle, and higher ones, where the causal impact varies across the variables pairs. Accordingly, the study outlines policy options consistent with the distributional patterns observed.
Citation - WoS: 4
Citation - Scopus: 4
Relationship between monetary policy and financial asset returns in Türkiye: Time- frequency- and quantile-based effects
(ELSEVIER, 2024) Tevfik Kartal; Ugur Korkut Pata; Dilvin Taskin; Talat Ulussever; Taskin, Dilvin; Pata, Ugur Korkut; Ulussever, Talat; Kartal, Mustafa Tevfik
This study analyzes the effect of monetary policy which are proxied by weighted average cost of funding (WACF) and Borsa Istanbul repurchase interest rate (REPO) on the returns of the main financial assets of monetary policy in T & uuml,rkiye. Using daily data between January 4 2011 and August 31 2023 the study applies novel nonlinear time-series methods such as wavelet coherence (WC) and quantile-on-quantile regression (QQ) as baseline methods and quantile regression (QR) for robustness. The findings demonstrate that (i) monetary policy has a stronger effect on financial asset returns at middle and higher frequencies across different periods, (ii) monetary policy has mainly declines (increases) effect on financial asset returns at lower and middle (higher) quantiles, (iii) the robustness of the outcomes is confirmed. Thus the outcomes show that monetary policy has a significant effect on financial asset returns and the effects vary across times across frequencies quantiles and financial assets.
Citation - WoS: 42
Citation - Scopus: 42
Role of energy transition in easing energy security risk and decreasing CO2 emissions: Disaggregated level evidence from the USA by quantile-based models
(Academic Press, 2024) Mustafa Tevfik Kartal; Dilvin Taşkın; Muhammad Shahbaz; Dervis Kirikkaleli; Serpil Kılıç Depren; Taşkın, Dilvin; Kirikkaleli, Derviş; Kılıç Depren, Serpil; Shahbaz, Muhammad; Depren, Serpil Kilic; Kartal, Mustafa Tevfik
Consistent with the increasing environmental interest the clean energy transition is highly critical to achieving decarbonization targets. Also energy security has become an important topic under the shadow of the energy crisis. Accordingly countries have been trying to stimulate clean energy use to preserve the environment and ensure energy security. So considering the leading role of economic size and volume of energy use the study examines the USA to define whether energy transition helps decrease energy security risk (ESR) and curb CO2 emissions. So the study applies a disaggregated level analysis by performing quantile-based models for the period from 2001/Q1 through 2022/Q4. The results demonstrate that (i) the energy transition index decreases environmental ESR at higher quantiles and reliability ESR at lower and middle quantiles whereas it is not beneficial in declining economic and geopolitical ESR, (ii) energy transition curbs CO2 emissions in building and transport sectors at lower quantiles whereas it does not help decrease CO2 emissions in industrial and power sectors, (iii) energy transition is mostly ineffective on ESR whereas it is highly effective in curbing CO2 emissions in all sectors except for transport across various quantiles as time passes, (iv) the results differ according to the aggregated and disaggregated levels, (v) the results are consistent across main and alternative models. Hence the study highlights the dominant effect of energy transition in curbing sectoral CO2 emissions rather than easing ESR. Accordingly the study discusses various policy implications for the USA. © 2024 Elsevier B.V. All rights reserved.
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.
Citation - WoS: 3
Citation - Scopus: 3
Time and frequency-based effect of energy-related R&D investments on power sector CO2 emissions: evidence from leading R&D investing countries by WLMC approach
(SPRINGER, 2025) Tevfik Kartal; Dilvin Taskin; Ahmed Imran Hunjra; Taşkın, Dilvin; Hunjra, Ahmed Imran; Kartal, Mustafa Tevfik
Environmental pollution has become highly important for countries and societies because climate change and global warming are stimulated by increasing carbon dioxide (CO2) emissions. Hence all related parties have been searching for solutions. Considering the high role of energy use in causing CO2 emissions energy-related research and development (R&D) investments are considered a strategic tool to curb the emissions. Accordingly the study analyzes the effect of energy-related R&D investments on power sector CO2 emissions. In doing so the study examines leading R&D investing countries (namely Canada-CAN, Switzerland-CHE, Germany-DEU, France-FRA, Japan-JPN, Norway-NOR, United States-USA) considering three R&D investment sub-types (i.e. energy efficiency R&D investments-EEF, renewable energy R&D investments-RRD, nuclear energy R&D investments-NRD) uses data from 1985/Q1 to 2022/Q4 and performs Wavelet Local Multiple Correlation (WLMC) approach to analyze over times and frequencies. The results show that (i) the effects of R&D investments are weak (strong) at lower (higher) frequencies, (ii) the effects of R&D investments vary based on times frequencies and countries, (iii) the most dominant R&D type is EEF (CHE DEU FRA & JPN) RRD (CAN & NOR) and NRD (USA), (iv) there is an important externality among R&D types. Thus the findings reveal the time frequency and country-based varying effect of R&D investments on power sector CO2 emissions implying a need for comprehensively balanced planning for R&D investments. Hence the countries should take the highly effective R&D investment types in combating power sector CO2 emissions allocate further budget to the effective ones and re-consider the budget distribution among the R&D types.