Browsing by Author "Demir, C"

Now showing 1 - 17 of 17
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    Does alternative energy usage converge across Oecd countries?
    Demir, C; Cergibozan, R
    The purpose of this study is to examine whether there exists a significant convergence process in the share of alternative energy use across 28 OECD (The Organisation for Economic Co-operation and Development) countries over the 1971-2015 period. Since energy resources are scarce and the most widely used energy sources might be harmful to the environment, seeking the productive, efficient and cleaner energy types becomes more important. Moreover, international institutions and agreements on the environment strongly recommend using these types of energy sources. From this point of view, the study suggests that these efforts on increasing the share of alternative energy use will cause a convergence process between countries. The findings obtained from the difference- and system-GMM (generalized method of moments) estimations reveal that there is a statistically significant convergence process across OECD countries and it is also observed that the speed of convergence is even higher when the country-specific economic and social factors are controlled. (C) 2019 Elsevier Ltd. All rights reserved.
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    THE ROLE OF FINANCIAL DEVELOPMENT ON THE SHARE OF RENEWABLE ENERGY IN JAPAN: A COMPREHENSIVE TIME-SERIES ANALYSIS
    Gök, A; Demir, C
    The purpose of this study is to analyze the effect of financial development (FD) on the share of renewable energy (RE) usage in Japan. The existing theoretical literature and empirical analyses covering different country cases reveal that FD might have positive, negative, or insignificant effect on RE use. Since there is no empirical investigation of the issue for Japan, the study aims to contribute to the literature. To that end, we used several time-series techniques to detect the association between RE usage and FD in Japan over the 1970-2020 period. The results obtained from the ARDL, Hatemi-J, Maki, Tsong et al. and NARDL cointegration tests showed that there is a significant cointegrated relationship between the share of RE use, FD, GDP per capita and trade openness. As for the long-run coefficients obtained from the ARDL, FMOLS, CCR and NARDL estimators revealed that increases in FD and trade openness raise the share of RE usage while increases in GDP per capita reduce it. Briefly, for the Japan case, we may suggest that improving the financial market structure of the country will bear fruit in terms of the share of cleaner and sustainable energy usage.
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    Income inequality and CO2 emissions: Empirical evidence from Turkey
    Demir, C; Cergibozan, R; Gök, A
    The aim of the study is to investigate the impact of income inequality on environmental quality in Turkey within the Environmental Kuznets Curve framework. In order to observe the short-run and long-run effects of income inequality on environmental quality, an autoregressive distributed lag bounds test on CO2 emission has been employed for the period 1963-2011 of Turkey. The results of the analysis reveal that there is a negative association between CO2 emission level and income inequality, which implies that increasing income inequality reduces environmental degradation in Turkey. Hence, a greater inequality in the society leads to less aggregate consumption in the economy due to lower propensity to emit in the richer households resulting in better environmental quality. The findings confirm an argument in the existing literature, which suggests that for developing countries, until a certain level of development, environmental degradation increases as income inequality in the society decreases. The results also confirm the Environmental Kuznets Curve hypothesis.
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    Environmental dimension of innovation: time series evidence from Turkey
    Demir, C; Cergibozan, R; Ari, A
    The study aims to investigate whether domestic innovation reduces environmental degradation in Turkey. Since the empirical literature on this subject is relatively poor and there is no empirical evidence for the Turkish case, the study attempts to bring a new perspective to the existing literature. To do this, the study estimates the relationship between innovation and CO2 emissions over the period of 1971-2013, via the ARDL bounds test and threshold cointegration test. Empirical results obtained from the ARDL approach indicates that the relationship between CO2 emission level and number of domestic patents depicts an inverted U-shape curve for Turkey. Moreover, estimation results show that urbanization, income level and financial development have positive effects on CO2 emissions, while alternative energy sources and human capital negatively affect the emission level. Since the linear econometric methods may yield inconsistent and biased results in the presence of a nonlinear relationship, the threshold cointegration method is employed as a robustness check. The findings obtained from threshold cointegration confirm the existence of a nonlinear relationship between CO2 emissions and domestic innovation. This suggests that for early stages of economic development, increases in domestic innovation raise the CO2 emission level in Turkey, but after achieving a certain development level, increases in domestic innovation lead to decreases in CO2 emissions. Thus, either developing or developed countries can eventually reduce CO2 emission levels by concentrating on innovation. Policy makers and institutions dealing with environmental issues should certainly pay attention to innovation and technological progress to assure a sustainable growth path.
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    Did Covid-19 Precautions and Lockdowns Cause Better Air Quality? Empirical Findings from Turkish Provinces
    Ari, A; Cergibozan, R; Demir, C
    The Covid-19 pandemic have dramatically affected the socio-economic structure in the world since governments put into action considerable precautions including lockdowns to reduce the speed of the contagion. Focusing on this point, we empirically investigate the environmental outcomes of the Covid-19 precautions and lockdowns in Turkey. The empirical analysis through the data obtained from different measurement stations indicate that the air pollution in the selected Turkish cities decreased due to the implemented precautions. The findings suggest that the Covid-19 might be an opportunity to rethink some economic and behavioral practices, as demonstrated by the reduction in the emission of air pollutants.
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    Macroeconomic Determinants of Stock Market Fluctuations: The Case of BIST-100
    Demir, C
    The purpose of this study is to analyze the impacts of some prominent macroeconomic factors on the Turkish Stock Market index, BIST-100 (Borsa Istanbul-100). For centuries, and mostly since the 20th century, stock markets are at the heart of economies. In our era, the largest economic crises arise from the stock market instabilities and thus, the stock markets are the focus of interest of the economy. Economists, investors, and policymakers try to predict the tendency of share prices, which substantially depend on foreign and domestic macroeconomic factors. Within this purpose, this study tries to investigate the impact of some selected macroeconomic factors on BIST-100 index over the 2003Q1-2017Q4 period. The findings obtained from the quarterly data via the ARDL Bounds Test suggest that economic growth, the relative value of the domestic currency, portfolio investments and foreign direct investments raise the stock market index while interest rate and crude oil prices negatively affect it. The results briefly reveal that the Istanbul Stock Exchange Market needs stronger domestic currency, higher international capital inflows, and lower energy and investment costs.
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    PUBLIC, PRIVATE OR UNIVERSITIES?: THE EFFECTIVENESS OF R&D EFFORTS IN OECD COUNTRIES
    Demir, C
    The aim of this study is to investigate the differential impacts of business, government and higher education sectors' research and development expenditures (R&D) on innovation in OECD countries. Although the business sector has the largest share of the R&D sector due to its profit motive, there are also some efforts made by public and higher education sectors. On the other hand, for decades, the literature of economics is in doubt about the efficiency of the public sector. The study deals with the issue by making a panel data analysis covering 18 OECD countries over the 1981-2016 period and aims to examine the separated effects of these sectoral R&D expenditures on innovation performance. Since most of the existing literature mostly focused on the R&D-GDP relationship, the present study aims to contribute to a relatively untouched point. To obtain robust findings, recent econometric tests and estimators have been used. The previous studies in the existing literature ignored the possibility of cross-sectional dependence problem within the country samples. Ignoring this problem may yield biased and inconsistent results. The present study considers the existence of cross-sectional dependence between selected countries and checks the robustness of each test and estimator via recent econometric techniques. The findings reveal firstly that there is a cointegrating relationship between the number of domestic patents (innovation) and the other three R&D indicators. Secondly, the long-run estimation results imply that increases in the R&D expenditures made by business sector significantly raise innovation while there is no statistically significant evidence on the impact of R&D expenditures made by the government and higher education sectors. The findings reveal that the R&D efforts made by the government and higher education sectors cannot turn into innovation and do not contribute to the knowledge spillover mechanism.
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    The Asymmetric Relationship Among Industrial Production, Capacity Utilization Rate, and Producer Prices in Türkiye: The Nonlinear ARDL Model Approach
    Demir, C; Özcan, SE
    This study investigates the asymmetric impacts of capacity utilization rate and producer prices on the industrial production index in T & uuml;rkiye over the 2007:1-2022:9 period. Approximating actual capacity to full capacity and enabling firms to produce at lower costs are primary macroeconomic objectives for every country. Therefore, Increases in capacity utilization are expected to positively affect and increases in producer prices affect to negatively affect industrial production. This study examined whether or not these factors cause asymmetric increases and decreases in industrial production. According to the nonlinear autoregressive distributed lag (NARDL) model results, a 1% increase in the capacity utilization rate raises industrial production by 1.63% while a 1% decrease in the same factor reduces industrial production by 1.27%. On the other hand, a 1% increase in producer prices reduces industrial production by 0.06% while decreases in the same factor have no statistically significant impact. The fact that positive and negative shocks do not affect at the same rate implies that the shocks from capacity utilization rate and producer prices on industrial production have an asymmetric structure. This evidence has also been proven through the rejection of the symmetry hypotheses as tested by the Wald test.
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    Do air quality and green space reduce propensity to crime?: an empirical investigation of OECD countries
    Demir, C; Ozcan, SE
    PurposeThis study investigates the impacts of green space and air quality on crime rates for Organisation for Economic Co-operation and Development (OECD) countries over the 2003-2017 period.Design/methodology/approachBy building an international data set, including both green space and air pollution at the same time in the model, and considering the potential endogeneities between variables, the study brings some novelties to the existing literature. Using the United Nations Crime Trends Survey and World Development Indicators databases, a panel data set of 37 OECD countries for 2003-2017 period was collected. To avoid the potential endogenous relationships between variables, the system-Generalized Method of Moments (system-GMM) method was applied.FindingsThe findings suggest that increases in green space reduce the crime rate, while increases in air pollution raise it. Additionally, the estimated control variables show that there are many statistically significant factors that determine the crime rate. In all the additional models, the effects of green space and air pollution were estimated consistently, which can be taken as a sign that the findings are robust.Originality/valueThe evidence of the study explicitly reveals that environmentally friendly policies provide benefits in terms of reducing crime rates as well as other known benefits. On the other hand, to represent the environmental dimension, this is the first study which uses a cross-country data set including both green space and air pollution in the model at the same time. Second, the issue has not been previously dealt with for OECD countries. Thirdly, the study considered the potential endogeneity between variables, and to check the robustness of the findings, some prominent factors affecting the crime rate were used as control variables.
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    Research Publications from the ATS MECOR Program in Turkiye
    Karakurt, Z; Yilmaz, O; Arikan, H; Ay, P; Demir, C; Gurkan, CG; Akgun, M; Buist, S
    Background: The American Thoracic Society (ATS) Methods in Epidemiologic, Clinical, and Operations Research (MECOR) Program aims to build research capacity in low and middle-income countries. MECOR has three levels, during which students learn to develop a research protocol and write a manuscript. MECOR Turkiye has been offered every year since 2008.Objective: The aim of this paper is to report the number and impact of published articles generated from research questions developed by students in levels 1, 2, and 3 of the ATS MECOR Program in Turkiye between 2008 and 2018.Methods: We collected the research questions developed in all levels of the ATS MECOR Program in Turkiye between 2008 and 2018. We searched Google Scholar, PubMed, Web of Science, and ResearchGate in April 2022 to see how many of these research questions were published as articles and, if published, in which journals.Results: Of the 176 research questions collected, 49 had been developed in level 1, 82 had been developed in level 2, and 45 had been developed in level 3. Of those 176 research questions, 55 (31.3%) generated articles that were accepted for publication. The frequency of published articles based on MECOR-developed research questions increased linearly as the course level in which they were developed increased (18.4% in level 1, 30% in level 2, 46.7% in level 3; P = 0.012; linear-by-linear association, P = 0.003). The median time from the development of the research question to publication was three years overall and did not differ significantly among the course levels (P = 0.36). Of the research questions developed, 43 were published in Science Citation Index or Science Citation Index Expanded-indexed journals.Conclusion: Acceptance of an article for publication is one way to measure the impact of the ATS MECOR Program. Our data describe significant research output among our participants, which increases with their length of participation in the program.
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    Publication Results of the Methods in Epidemiological Clinical and Operations Research (MECOR) Program in Turkey
    Karakurt, Z; Yilmaz, O; Arikan, H; Ay, P; Demir, C; Gurkan, CG; Akgun, M; Buist, S
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    Nodular lymphocyte predominant Hodgkin's lymphoma in daily practice: A multicenter experience
    Gemici, A; Aydogdu, I; Terzi, H; Sencan, M; Aslan, A; Kaya, AH; Dal, MS; Akay, MO; Dogu, MH; Ayyildiz, O; Sahin, F; Cagliyan, GA; Yilmaz, M; Gokgoz, Z; Bilen, Y; Demir, C; Sevindik, OG; Korkmaz, S; Eser, B; Altuntas, F
    Nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL) is a rare subtype of Hodgkin's lymphoma. In this study, we aimed to investigate the clinical features and therapeutic outcomes of patients with NLPHL who were diagnosed at different institutes in Turkey. We retrospectively reviewed the records of the patients diagnosed with NLPHL. Adult patients who were diagnosed after 2005 with histological confirmation were selected for the study. Forty-three patients were included in the study. Median age of patients was 37.5years (18-70) at the time of diagnosis. About 60.5% patients were diagnosed as stage I and II NLPHL, and remaining 39.5% had stage III and IV disease. Median follow-up was 46months. During follow-up, none of the patients died. Seven patients relapsed or progressed after initial therapy at a median of 12months. Five of 7 relapsed/refractory patients (71.4%) were salvaged with chemotherapy only (DHAP, ICE), and the remaining 2 (28.6%) were salvaged with chemoimmunotherapy. All of relapsed/refractory patients were able to achieve complete remission after salvage therapy. Lactate dehydrogenase levels were significantly higher in patients with progressive disease compared with nonprogressive disease. Our study showed an excellent outcome with all patients alive at last contact with a median follow up of 46months despite a wide range of different therapeutic approaches. All relapsed and refractory patients were successfully salvaged despite a low frequency of patients received immunotherapy in conjunction with chemotherapy. Our results suggest that immunotherapy may be reserved for further relapses.
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    Primary central nervous system lymphoma in daily practice and the role of autologous stem cell transplantation in relapsed disease: A retrospective multicenter study
    Erkurt, MA; Berber, I; Tekgunduz, E; Dogu, MH; Korkmaz, S; Demir, C; Yilmaz, M; Akay, OM; Pala, C; Bilen, Y; Kaya, E; Sari, I; Sencan, M; Kuku, I; Altuntas, F; Dal, MS; Aydogdu, I
    We investigated the course of 54 patients presenting with primary central nervous system lymphoma, who were treated in daily practice. The patients were treated with chemotherapy and/or radiotherapy and/or intrathecal chemotherapy. At a median follow-up period of 23 months (range 1-71), median relapse-free survival (RFS) and overall survival (OS) were not reached. Estimated 2-year RFS and OS rates were 42% and 48%, respectively. Ten relapsed PCNSL patients underwent ASCT. Complete remission rate of these patients was 40%, with 20% treatment-related mortality. Estimated 2-year RFS and OS rates were 37% and 40%, respectively. The prognosis of patients with PCNSL, who received off-study treatment, is still dismal. (c) 2016 Elsevier Ltd. All rights reserved.
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    COVID-19 Pandemic and the Global Perspective of Turkish Thoracic Society
    Köktürk, N; Itil, BO; Altinisik, G; Adigüzel, N; Akgün, M; Akyildiz, L; Altin, S; Arikan, H; Ates, G; Ay, P; Aykaç, N; Babayigit, C; Bostan, P; Cinel, G; Çalisir, HC; Çelik, P; Çetinkaya, PD; Dagli, E; Demir, AU; Demir, C; Dikensoy, Ö; Edis, EÇ; Elbek, O; Erdinç, M; Ergan, B; Eyüboglu, AFÖ; Gemicioglu, B; Göksel, T; Gülhan, E; Gültekin, Ö; Gürkan, CG; Gürgün, A; Havlucu, Y; Basoglu, OK; Karakurt, S; Karkurt, Z; Kilinç, O; Kocabas, A; Kul, S; Müsellim, B; Nayci, S; Özkan, M; Pinarer, Ö; Saltürk, C; Sandal, A; Sayiner, A; Sen, E; Simsek, GÖ; Karadag, BT; Akyil, FT; Töreyin, ZN; Uçan, ES; Küçük, FÇU; Varol, A; Yasin, Y; Yildiz, T; Yorgancioglu, AA; Bayram, H
    It has been more than 3 months now since the first case of COVID-19 was reported in Turkey. Globally, the number of confirmed cases and deaths reached 9,653,048 and 491,128 respectively, as reported by 216 countries by June 27, 2020. Turkey had 1,396 new cases, 194,511 total cases, and 5,065 deaths by the same date. From the first case until today, the Turkish Thoracic Society (TTS) has been very proactive in educating doctors, increasing public awareness, undertaking academic studies, and assisting with public health policies. In the present report, social, academic, and management perspectives of the pandemic are presented under appropriate subtitles. During this critical public health crisis, TTS has once again demonstrated its readiness and constructive stance by supporting public health, healthcare workers, and the environment. This review summarizes the perspective of TTS on each aspect of the COVID-19 pandemic and casts light on its contributions.
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    International Forum: The Turkish perspective on apheresis activity: The Turkish apheresis registry report
    Ozatli, D; Giden, AO; Erkurt, MA; Korkmaz, S; Basci, S; Ulas, T; Turgut, B; Yigenoglu, TN; Hacibekiroglu, T; Basturk, A; Dal, MS; Namdaroglu, S; Hindilerden, F; Hacioglu, SK; Cagliyan, GA; Ilhan, G; Kacmaz, M; Uysal, A; Merter, M; Ekinci, O; Dursun, FE; Tekinalp, A; Demircioglu, S; Sincan, G; Acik, DY; Akdeniz, A; Ucar, MA; Yeral, M; Ciftciler, R; Teke, HU; Umit, EG; Karakus, A; Bilen, Y; Yokus, O; Albayrak, M; Demir, C; Okan, V; Serefhanoglu, S; Karti, S; Ozkurt, ZN; Eser, B; Aydogdu, I; Kuku, I; Cagirgan, S; Sonmez, M; Ozet, G; Altuntas, F
    Therapeutic apheresis is an extracorporeal treatment that selectively removes abnormal cells or harmful sub-stances in the blood that are associated with or cause certain diseases. During the last decades the application of therapeutic apheresis has expanded to a broad spectrum of hematological and non-hematological diseases due to various studies on the clinical efficacy of this procedure. In this context there are more than 30 centers per-forming therapeutic apheresis and registered in the apheresis database in Turkey. Herein, we, The Turkish Apheresis Registry, aimed to analyze some key articles published so far from Turkey regarding the use of apheresis for various indications.
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    Intellectual property rights and global imitation chains: the north-south-east model
    Demir, C; Lenger, A
    This study investigates the effects of intellectual property rights (IPR) protection on economies by proposing a three-pole global economy model. The main proposition of the study is that the classical two-pole approach (north-south) does not reflect the technological heterogeneity and conflicts within the developing world. Therefore, a three-pole world economy model which consists of the following regions has been designed; the north which innovates the northern products, the east which innovates the eastern products and also tries to imitate the northern products, and lastly, the south which tries to imitate both the eastern products and the northern products that have been already imitated by the east. Thus, the model suggests a world system depending on global imitation chains. The numeric simulation results reveal firstly, the northern region benefits from tighter IPR policies in any case; secondly, stronger protection of IPR certainly exerts negative effects in the south while it brings benefits the eastern region in a way that highlights the main contribution of the paper.