Browsing by Author "Berk, Istemi"

Now showing 1 - 5 of 5

Citation - WoS: 53
Citation - Scopus: 58
Crude Oil Import Policy of Turkey: Historical Analysis of Determinants and Implications Since 1968
(Elsevier Sci Ltd, 2011) Ediger, Volkan S.; Berk, Istemi
Turkey is one of the most energy import dependent countries in the world, suffering deeply from the economic and strategic burdens of oil importation. Our purpose is to determine the factors behind the crude oil import policy of Turkey and to measure their contribution to a well-organized import strategy. We implemented a principle component analysis to construct an Oil Import Vulnerability Index (OIVI) based on four factors, which are crude oil import dependency of primary energy consumption, crude oil import bill as a share of Gross Domestic Product (GDP), non-diversification of import sources, and share of oil in total energy import. The contribution of these factors to the OIVI is found to be approximately equal. While an overall deterioration in the OIVI has been observed during periods of increasing oil prices, better diversification of oil import sources has lead to significant improvements. We suggest Turkish policy-makers implement sound policies, emphasizing diversification of crude oil import sources and reduction of the share of crude oil in primary energy imports to increase energy supply security. This study has also demonstrated that it is possible to construct an index representing crude oil vulnerability caused by import dependency. (C) 2011 Elsevier Ltd. All rights reserved.
Citation - WoS: 39
Citation - Scopus: 48
Energy Prices and Economic Growth in the Long Run: Theory and Evidence
(Pergamon-Elsevier Science Ltd, 2014) Berk, Istemi; Yetkiner, Hakan
In this paper, we attempt to derive and test the role of energy prices on economic growth. We first developed a two-sector endogenous growth model, based on J Polit Economy 1991; 99:500-521. We modified the model such that consumption goods sector uses energy as an input along with capital. The model allows us to show that the growth rate of energy price has a negative effect on the growth rates of energy use and real GDP. Following this, derived theoretical relationships between energy prices and economic growth and energy consumption were tested empirically using error-correction based panel cointegration tests and panel Autoregressive Distributed Lag (ARDL) approach. We applied this methodology on data of composite energy prices, GDP per capita and energy consumption per capita for sixteen countries for the period between 1978 and 2011. We found significant cointegration between energy prices and real GDP per capita, as well as between energy prices and energy consumption per capita. Moreover, long-run estimates reveal negative and significant effects of composite energy prices on both GDP per capita and energy consumption per capita. We suggest that increasing the share of renewable energy sources in energy consumption would help policy-makers to control permanent long-term increases in consumer energy prices, in turn leading to an increase in economic growth, and hence in welfare. This paper contributes to the literature by highlighting the existence of a previously neglected welfare-improving channel of renewable energy. (C) 2014 Elsevier Ltd. All rights reserved.
Citation - Scopus: 1
Life Cycle Assessment of Black Tea Production and Consumption in Turkiye: Insights From Waste Management Scenarios
(Elsevier, 2025) Uctug, Fehmi Gorkem; Ediger, Volkan S.; Kucuker, Mehmet Ali; Berk, Istemi; Inan, Ali; Tugcu, Melisa
This study conducts a life cycle assessment (LCA) of tea production and consumption in T & uuml;rkiye, the world leader in per capita tea consumption. Aiming to identify environmental hotspots and propose sustainable solutions, a cradle-to-grave LCA was performed using CCaLC2 software, CML methodology, and the Ecoinvent 3.0 database. It covers cultivation, processing, transportation, and consumption stages, focusing on key environmental indicators like carbon footprint and acidification potential. The results reveal that consumption dominates the environmental footprint (91%) due to energy-intensive brewing methods. Cultivation and transportation contribute minimally (4% each). This highlights the need for promoting energy-efficient brewing practices and consumer adoption of renewable energy sources. The study also explores the environmental implications of different waste management strategies. Composting emerged as the most beneficial approach for reducing the carbon footprint and photochemical oxidants creation, while incineration might be preferable for other impact categories. This study underscores the importance of addressing energy consumption during tea brewing and encouraging renewable energy use among consumers. Additionally, it promotes composting as a crucial waste management strategy for a more sustainable tea value chain in T & uuml;rkiye. These findings offer valuable insights for policymakers, industry players, and tea drinkers to make informed decisions that minimize environmental impact.
Citation - WoS: 117
Citation - Scopus: 132
Towards a Common Renewable Future: the System-Gmm Approach To Assess the Convergence in Renewable Energy Consumption of Eu Countries
(Elsevier, 2020) Berk, Istemi; Kasman, Adnan; Kilinc, Dilara
This paper investigates whether the contribution of renewable energy sources to primary energy consumption is characterized by a convergence process across core European Union (EU) countries over the period from 1990 to 2014. The System Generalized Method of Moments (GMM) methodology is employed for 5-year span panel data of 14 EU members. The findings indicate strong evidence for both the absolute (unconditional) and conditional convergence of renewables' share in primary energy consumption across EU-14 countries. Moreover, the control variables, namely CO2 emissions per GDP, FDI inward stock and electricity prices contribute to the speed of convergence. Hence, the (implicit) rate of conditional convergence is higher than that of absolute convergence. The empirical evidence suggests that the energy mixes of core EU members have a tendency to become similar in the long-run as the shares of RES in primary energy consumption converge to the average level. Nonetheless, it does not necessarily imply that this average would be 20% target, which is to be achieved by 2020 according to EU directive 2009/28/EC. (C) 2018 Elsevier B.V. All rights reserved.
Citation - WoS: 11
Citation - Scopus: 11
A Unified Theory and Evidence on Co2 Emissions Convergence
(Springer Heidelberg, 2022) Berk, Istemi; Onater-Isberk, Esra; Yetkiner, Hakan
The objective of this paper is to develop and test a sound theory of CO2 emissions convergence equation. To this end, we modify the Solow growth model by including depleting energy as a factor of production and by defining the channel through which CO2 emissions are created. Then, we empirically estimate the derived per capita CO2 emissions convergence equation employing system GMM approach on a panel dataset of 65 countries over the period 1970 to 2014. Results present strong evidence towards the existence of convergence for the global sample over the whole period. We also find that, in terms of per capita CO2 emissions, Annex I parties of UNFCCC converge, while non-Annex countries diverge. Our robustness check via stochastic convergence tests confirms our system GMM results for Annex I countries.