Ekonomi Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1936

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Citation - WoS: 7
Citation - Scopus: 8
Hematocrit Levels and Thrombotic Events in Patients With Polycythemia Vera: an Analysis of Veterans Health Administration Data
(Springer, 2019) Parasuraman, Shreekant; Robyn Scherber; Jingbo Yu; Li Wang; Dilan Paranagama; Sulena Shrestha; Başer, Onur
Patients with polycythemia vera (PV) have a high incidence of thrombotic events (TEs), contributing to a greater mortality risk than the general population. The relationship between hematocrit (HCT) levels and TE occurrence among patients with PV from the Veterans Health Administration (VHA) was evaluated to replicate findings of the CYTO-PV trial with a real-world patient population. This retrospective study used VHA medical record and claims data from the first claim with a PV diagnosis (index) until death, disenrollment, or end of study, collected between October 1, 2005, and September 30, 2012. Patients were aged ? 18 years at index, had ? 2 claims for PV (ICD-9-CM code, 238.4) ? 30 days apart during the identification period, continuous health plan enrollment from 12 months pre-index until end of study, and ? 3 HCT measurements per year during follow-up. This analysis focused on patients with no pre-index TE, and with all HCT values either < 45% or ? 45% during the follow-up period. The difference in TE risk between HCT groups was assessed using unadjusted Cox regression models based on time to first TE. Patients (N = 213) were mean (SD) age 68.9 (11.5) years, 98.6% male, and 61.5% white. TE rates for patients with HCT values < 45% versus ? 45% were 40.3% and 54.2%, respectively. Among patients with ? 1 HCT before TE, TE risk hazard ratio was 1.61 (95% CI, 1.03–2.51; P = 0.036). This analysis of the VHA population further supports effective monitoring and control of HCT levels < 45% to reduce TE risk in patients with PV.
Citation - WoS: 3
Citation - Scopus: 3
Warfarin Discontinuation in Patientswith Unprovoked Venous Thromboembolism: a Large Us Insurance Database Analysis
(2016) Mardekian, Jack; Liu, Xianchen; Phatak, Hemant; Xie, Lin; Tan, Wilson; Başer, Onur; Ramacciotti, Eduardo
This study examined warfarin therapy discontinuation and its risk factors among patients with unprovoked venous thromboembolism (VTE) in the US clinical practice setting. Adult patients with unprovoked VTE were identified from the MarketScan claims database from January 1, 2006 to December 31, 2012. The index date was defined as the date of first VTE diagnosis. Patients were required to have no VTE diagnosis in the 6 months before index date and continuous health plan enrollment for 6 months before and 12 months after the index date. Warfarin discontinuation rates and adjusted hazard ratios (HRs) were reported. Of 21,163 eligible patients, 15,463 were diagnosed with deep vein thrombosis (DVT) only (73.1%), 5027 with pulmonary embolism (PE) only (23.7%), and 673 with DVT and PE (3.2%). The average duration of warfarin therapy was 5.2 months (SD = 3.0). During 1-year follow-up, 21.4% patients discontinued therapy within 3 months, 42.8% within 6 months, and 70.1% within 12 months. PE versus DVT [HR = 0.77, 95% confidence interval (CI) = 0.74-0.80], comorbid atrial fibrillation (HR = 0.73, 95% CI = 0.66-0.81), thrombophilia (HR = 0.62, 95% CI = 0.54-0.71), and age >40 years (41-65 years: HR = 0.86, 95% CI = 0.81-0.91; >65 years: HR = 0.82, 95% CI = 0.77-0.87) were significantly associated with reduced risk of warfarin discontinuation. Alcohol abuse/dependence (HR = 1.36, 95% CI = 1.20-1.55), cancer history (HR = 1.13, 95% CI = 1.07-1.19), bleeding (HR = 1.07, 95% CI = 1.01-1.15), and catheter ablation (HR = 1.10, 95% CI = 1.00-1.20) in the 6 months before index date were significantly associated with increased risk for warfarin discontinuation. In conclusion, nearly 1 of 4 patients with unprovoked VTE discontinued warfarin within 3 months. Three of 4 patients discontinued therapy within 1 year. Younger age and multiple clinical factors are associated with warfarin therapy discontinuation.
Citation - WoS: 3
Citation - Scopus: 4
State–business Relations, Financial Access and Firm Performance: a Causal Mediation Analysis
(Wiley, 2020) Karahasan, Burhan Can; Bilgel, Fırat
This study investigates the triangular relationship among state–business relations, financial access and economic performance in the Middle East and North Africa. We hypothesize that financial intermediation is a significant mediating factor in the relationship between state–business relations and firm performance. Employing a causal mediation analysis, results show that inefficient ties with the state are a cause of poor firm performance. Inefficient state–business relations reduce firm performance by 2.3 to 4.4 per cent through access to finance and by 12 to 40 per cent via its direct effect. About 3 to 16 per cent of the total effect is mediated through financial access, while the remaining is the direct effect.
Citation - Scopus: 1
Infant Mortality in Turkey: Causes and Effects in a Regional Context
(Wiley, 2020) Bilgel, Firat
This study attempts to identify the causal and/or direct effects of sociocultural determinants of infant mortality in Turkey within a regional context using causal graph analysis and global and local spatial models. The conceptual framework, combined with the data, shows that fertility and consanguinity have direct effects on infant mortality rates, and that female illiteracy, as a proxy for maternal education, is the main cause of rising infant mortality even in the presence of latent confounding. The surface of estimates further shows that the local effects of female illiteracy and consanguinity are non-stationary across space, calling for location-specific policies.
Citation - WoS: 25
Citation - Scopus: 25
Impact of Switching From an Initial Tumor Necrosis Factor Inhibitor on Health Care Resource Utilization and Costs Among Patients With Rheumatoid Arthritis
(2015) Roy, Sanjoy; Ganguli, Arijit; Xie, Lin; Başer, Onur; Cifaldi, Mary
Purpose: Despite improved clinical outcomes for the majority of patients, nearly 30% of patients with rheumatoid arthritis (RA) who initiate tumor necrosis factor antagonist (anti-TNF) biologic agents fail to respond to their first-line anti-TNF and switch to another anti-TNF or a non-TNF biologic. How this change affects health care costs and resource utilization is unknown. We therefore compared RA patients taking first-line anti-TNFs who switched to a second anti-TNF versus those patients who switched to an alternate biologic. Methods: Health care claims data were obtained from a large US database for eligible adults with confirmed RA diagnoses who initiated anti-TNF treatment and switched to another biologic. Health care costs and utilization during the first 12 months' postswitch were compared. Generalized linear models were used to adjust for differences in demographic and clinical characteristics before switching. Findings: Patients who switched to a second anti-TNF rather than a non-TNF biologic were generally younger (53.0 vs. 55.3 years; P < 0.0001) and less likely to be female (79.7% vs. 82.7%; P = 0.0490). Of the 3497 eligible patients who switched from first-line anti-TNFs, 2563 (73.3%) switched to another anti-TNF and 934 (26.7%) switched to a non-TNF. Adalimumab was the most frequently prescribed (43.4%) second-line anti-TNF, and abatacept was the most common non anti-TNF (71.4%). Patients who switched to a second anti-TNF remained on their first medication for a significantly shorter period (342.5 vs 420.6 days; P < 0.0001) and had lower comorbidity indices and higher disease severity at baseline than those who switched to a non anti-TNF. After adjusting for baseline differences, patients who switched to second anti-TNFs versus a non-TNF incurred lower RA-related costs ($20,938.9 vs $22,645.2; P = 0.0010) and total health care costs ($34,894.6 vs $38,437.2; P = 0.0010) 1 year postswitch. These differences were driven by increased physician office visit costs among the non-TNF group. Implications: Among the anti-TNF initiators who switched therapy, more patients switched to a second anti-TNF than to a non-TNF. Switching to a second anti-TNF treatment was associated with lower all-cause and RA-related health care costs and resource utilization than switching to a non-TNF. Because switching therapy may be unavoidable, finding a treatment algorithm mitigating this increase to any extent should be considered. These data are limited by their retrospective design. Additional confounding variables that could not be controlled for may affect results. (C) 2015 The Authors. Published by Elsevier HS journals, Inc.
Citation - WoS: 4
Citation - Scopus: 2
The Economic Impact of Symptomatic Menopause Among Low-Socioeconomic Women in the United States
(2016) Başer, Onur; Keshishian, A; Xie, Lin; Wang, Yuexi
Background: Menopausal symptoms have a significant negative impact on patient's quality of life and increase healthcare costs among women. Methods: This retrospective analysis used data from a U.S. national database (01 January 2008-31 December 2010). Patients with a diagnosis of menopause symptoms or a prescription claim for hormone therapy were matched to control patients. Healthcare resource utilization and costs during the 6-month follow-up period were compared. Generalized linear models were used to adjust for differences in baseline and demographic characteristics between the cohorts. Results: A total of 71,076 patients were included in each cohort. Patients with menopausal symptoms were more likely to have depression and anxiety and incurred significantly higher follow-up healthcare costs ($7237 vs $6739, p < 0.001) and healthcare utilization during the 6-month follow-up period. Conclusion: Patients diagnosed with menopausal symptoms or treated with hormone therapy incurred significantly higher healthcare costs than those without menopausal symptoms or treatment.
Understanding Covid-19 Mobility Through Human Capital: a Unified Causal Framework
(Springer, 2023) Bilgel, Fırat; Karahasan, Burhan Can
This paper seeks to identify the causal impact of educational human capital on social distancing behavior at workplace in Turkey using district-level data for the period of April 2020 - February 2021. We adopt a unified causal framework, predicated on domain knowledge, theory-justified constraints anda data-driven causal structure discovery using causal graphs. We answer our causal query by employing machine learning prediction algorithms; instrumental variables in the presence of latent confounding and Heckman's model in the presence of selection bias. Results show that educated regions are able to distance-work and educational human capital is a key factor in reducing workplace mobility, possibly through its impact on employment. This pattern leads to higher workplace mobility for less educated regions and translates into higher Covid-19 infection rates. The future of the pandemic lies in less educated segments of developing countries and calls for public health action to decrease its unequal and pervasive impact.
Unemployment Polarisation and Club Convergence in Türkiye
(Wiley, 2025) Karahasan, Burhan Can
Turkish economy has undergone massive transformation during the 2000s. Annual economic growth reached a peak of 10% in the early 2000s. However, the side effects of global financial crises and the internal macroeconomic imbalances shift the growth trajectory of T & uuml;rkiye into a new path of unstable economic growth. While macroeconomic consequences are densely discussed we know less about the adjustment of local labour markets. To fill this gap, we examine the club formation of Turkish regions by analysing their unemployment trajectories during the post 2000s. Our findings show that despite rapid economic growth Turkish regions get extremely polarised and form distinct convergence clubs. Remarkably polarisation is higher for the female population. Geographically, polarisation is in the form of an isolation for the least developed south-eastern regions and some of the developed urbanised western regions. Additionally, our robustness exercises indicate higher polarisation after 2013 as Turkish economic growth starts to become more volatile and less sustainable. Finally, our spatial extensions show that impact of spatial proximity has significant influence on the accurate extent of unemployment deprivation.
State Gun Control Laws, Gun Ownership and the Supply of Homicide Organ Donors
(Elsevier, 2020) Bilgel, Fırat
The likelihood of being a potential deceased organ donor is higher for individuals who have been exposed to situations typically characterized by a severe head trauma or stroke that result in brain death. Employing count data models that account for overdispersion and/or excessive counts of zeros, this paper assesses the unintended consequences of enforcing stricter gun control laws and the effects of gun ownership on homicide organ donor supply in the United States using county data for the period 2009–2015. The findings confirm the transplantation paradox hypothesis that stricter gun control laws reduce the expected cases of gun homicides and thereby reduce deceased organ donor supply and exacerbate the organ shortage. The findings are robust to several measures of the strength of gun control laws, restricted samples and spurious outcome variables. However, the direction of the impact of gun ownership levels on homicide organ donor supply proved to be inconclusive.
Network Among Hta Ecosystem
(Springer Verlag, 2019) Çınaroğlu, Songül; Başer, Onur
This study intends to examine the main drivers of network relations among health technology assessment (HTA) organizations. Social network analysis was performed to determine the relations among HTA organizations and to visualize the main drivers of such collaboration. The members in HTA organizations such as International Society for Pharmacoeconomics and Outcomes Research, Health Technology Assessment international, International Network of Agencies for Health Technology Assessment, EuroScan, European Network for Health Technology Assessment, HTAsiaLink, and Health Technology Assessment Network for the Americas are said to create networks. Ten different HTA organizations were considered in the analysis, including the Ministry of Health (MoH) organizations, universities, for-profit organizations, and hospitals. The Fruchterman-Reingold algorithm was used to perform networking, and the average clustering coefficient and average path length were examined to measure collaborative performance. The network graph of the HTA ecosystem shows the highest collaborative frequency among HTA organizations, which are the members of MoH organizations, government agencies, universities, and nonprofit organizations. The average path length was 2.21, and the average clustering coefficient was 36.57, indicating an obvious clustering effect. The study results highlight that networking within the HTA ecosystem is driven by government organizations. Boosting the integration of the private sector into the system and creating data-sharing strategies are essential to foster HTA collaboration. Because HTA is shaped by local dynamics and no gold standard exists for HTA implementation, encouraging collaborative efforts is the only way to avoid redundant efforts and make health technologies available for everyone.
Citation - WoS: 8
Citation - Scopus: 8
Out-Of International Normalized Ratio Values and Healthcare Cost Among New Warfarin Patients With Non-Valvular Atrial Fibrillation
(2015) Wang, Li; Nelson, Winnie W.; Schein, Jeffrey R.; Damaraju, Chandrasekharrao, V; Başer, Onur
Patients with out-of-range international normalized ratio (INR) values <2.0 and >3.0 have been associated with increased risk of thromboembolic and bleeding events. INR monitoring is costly, because of associated physician and nurse time, laboratory resource use, and dose adjustments.
Citation - WoS: 2
Citation - Scopus: 3
Determinants of Turkish Female Labour Force Participation: an Analysis With Manufacturing Firm-Level Data
(Taylor & Francis, 2020) Karamollaoğlu, Nazlı; Soybilgen, Barış
Compared to other developing countries, Turkey has a very low female labour participation rate. Previous studies usually focus on the labour supply side of female employment. Unlike the previous literature, this paper investigates firm-level determinants of female employment in manufacturing firms using a unique micro data set constructed using different sources. After controlling for geographical variation, firm, and industry-specific factors, our results show that larger firms, exporter firms, firms with higher part-time worker ratio, and foreign-owned firms have higher female employment rate whereas younger firms, firms with higher labour productivity, and firms with long working hours have lower female employment rate.
Citation - WoS: 17
Citation - Scopus: 19
Oil Prices and Economic Activity in Brics and G7 Countries
(Springer, 2019) Kılıç, Erdem; Çankaya, Serkan
The effect of oil prices on countries’ economic activity has been the center of attention for decades. The empirical link between oil prices and economic activity has been steadily investigated during this time period but the measured outcomes have revealed mixed results and been inconsistent. This study examines the effect of oil prices on economic activity for Brazil, Russia, India, China, and South Africa (BRICS) and Group of Seven (G7) countries in both short-run and long-run relationships by estimating a maximum likelihood structural vector autoregression model. The model shows that a positive shock to oil prices tends to affect the monetary aggregate in Brazil, Canada, France, Germany, and Russia. The effect on interest rate spread is most significant in India and Russia. Impulse response functions display almost no effect on the gross domestic product in the US and China. A positive response on the consumer price index is observed mostly for developed countries. The response of real exchange rate reveals a positive effect on all countries in varying degrees, with the exception of the US and South Africa. Finally, Granger causality tests were conducted with proper allowance for the non-stationarity of the data. The findings illustrate that the Russian economy is among the economies that are most significantly affected by oil price fluctuations for almost all the selected variables. The models also reveal that the effect of oil price shocks on the US’s and China’s economic activities is only limited to the effect on real exchange rates. Other variables show no or limited reactions to oil prices. We also used the Markov switching maximum likelihood vector autoregression models, which reveals similar results.
Citation - WoS: 5
Citation - Scopus: 5
Evidence for Financial Contagion in Endogenous Volatile Periods
(Wiley, 2015) Ulusoy, Veysel; Kılıç, Erdem
The objective of this study is to analyze cross-border contagious dynamics in both foreign exchange markets and stock exchange markets. Propagation is analyzed with respect to the transmission of excessive volatility that is endogenously determined. The contagion process is discussed in the context of financial systems, foreign direct investments and trade. Implementing a vector autoregressive-multivariate generalized autoregressive conditional heteroskedasticity (VAR-MGARCH) model, we show that country-specific turbulence in financial markets is able to create unanticipated financial contagion across countries. Diversified trade and financial relations decrease the risk of exposure to contagion from external markets. The world's largest economies, however, play a price-setter role, and diversification is of secondary importance. Asymmetric transmission of the empirically predicted contagion prevails in the latter case.
Citation - WoS: 6
Citation - Scopus: 9
Gendering Resistance: Multiple Faces of the Kurdish Women's Struggle
(Wiley, 2019) Göksel, Nisa
The article explores the Kurdish women's movement in Turkey by bridging two forms of resistance: those of guerrilla women fighters and of activist women. Based on my extensive ethnographic and archival research, I ask how women under conditions of war engage in different modes of resistance. In what ways does the "heroic resistance" of guerrilla women resonate with and/or contradict the everyday, "ordinary" struggles of activist women? The potent image of the Kurdish guerrilla woman that emerged in the early 1990s is constitutive of many other modes of political subjectivities, even among women who do not or cannot become guerrillas. One of those subjectivities is that of the activist woman. My analysis suggests that women's activism opens up a middle ground of action between "heroic" and "ordinary" resistance by reconciling revolutionary politics with everyday activism around gender-based violence, democracy, and human rights. Although both revolutionary movement participants and scholars of revolutionary resistance often contrast the "ordinary" with the realm of armed resistance, this article challenges this dichotomy. I take the two realms of resistance-the ordinary and the heroic-as the core constituents of revolutionary resistance, and I reconsider the gendered interplay between them.
Citation - WoS: 4
Citation - Scopus: 6
Does the Unification of Health Financing Affect the Distribution Pattern of Out-Of Health Expenses in Turkey?
(Wiley, 2019) Çınaroğlu, Songül; Başer, Onur
Turkey has implemented health reforms for over a decade and has taken significant steps toward unifying health financing. This study investigated the financial burden associated with out-of-pocket (OOP) expenditures under universal health coverage, using national 2003–2015 household budget data from the Turkish Statistical Institute. Progress was evaluated using Kakwani–Suits indices and Lorenz concentration curves. The results indicate that overall, more than a decade after its unification, redistribution of wealth in the Turkish health financing system has benefitted the wealthy but not the poor. Both curve and index approaches (Kakwani index 2003 = -0.50; 2015 = -0.44) reveal an increasingly regressive pattern of OOP health expenditures. The effective use of fiscal space and good political leadership are essential for the successful continuation of reforms to combat poverty in Turkey.
Citation - WoS: 17
Citation - Scopus: 20
Consumer Confidence and Economic Activity: a Factor Augmented Var Approach
(Taylor & Francis, 2016) Kılıç, Erdem; Çankaya, Serkan
This study aims to analyse the effects of the consumer confidence on economic activity for the USmarket. We use the empirical factor-augmented vector autoregression (FAVAR) method, whichenables us to incorporate a wide range of economic activity factors into the analysis. Theconsumer confidence index (CCI) is chosen as the principal variable that is presumed to representthe degree of optimism on the state of economic activity. The results show that consumerconfidence and economic activity are strongly correlated for manufacturing-related factors,such as industrial production and inventories. We also observe strong relation among CCI andpersonal consumption expenditures, as well as housing market variables.
Citation - WoS: 3
Citation - Scopus: 3
Efficiency Analysis of Social Performance – the Case of Turkish Super League
(Taylor & Francis, 2020) Donduran, Murat; Özaydın, Selçuk
Undoubtedly, due to its impact on both revenues and the home advantage, social performance is a key factor of success for football clubs. Growing revenues and the government’s eagerness to promote football in Turkey in recent years have created desirable conditions for Turkish clubs. However, research into the impact of social performance success has not received much attention, especially in Turkey, despite Turkey being one of the major leagues in Europe. This study aims to fill this gap in the literature. It does so by investigating social performance using a two-stage stochastic frontier analysis drawing on evidence from the Turkish Super League between the 2012/2013 and 2017/2018 seasons. Results from the first stage illustrate that social efficiency leaders change almost every season. Results from the second stage of research identify which specific factors are diminishing the social technical efficiency for clubs in the Turkish Super League. It emerges that the fundamental source of social inefficiency in Turkey is the Passolig, an identification system implemented in 2014. Furthermore, it transpires that heterogeneity among the clubs’ hometowns is also highly influential on social efficiency. However, even though attendance has managed to recover back to pre-Passolig levels, social efficiency is still lower than the pre-Passolig levels.
Citation - WoS: 46
Citation - Scopus: 70
Adoption and Use of Learning Management Systems in Education: the Role of Playfulness and Self-Management
(MDPI [Commercial Publisher], 2021) Akküçük, Ulaş; Balkaya, Selen
This article investigates the factors affecting primary and secondary education teachers' behavioral intention to adopt learning management systems (LMSs). Information technology (IT) innovations have the power to change the way we work, educate, learn, and basically the way we live. The effect of IT innovations on education makes it critical to understand the current usage situation of LMSs and the factors affecting their adoption by teachers. The unified theory of acceptance and use of technology (UTAUT) was extended with factors from education and game-based learning literature. In order to see the effect of individual- and organizational-level characteristics, multi-group structural equation modeling (SEM) analysis was conducted and discrepancies in relationships were reported. Evaluation of users and non-users and teachers of different fields were also compared to each other. The findings of this study not only contribute to theory through the development and testing of a thorough model relating technology features and individual characteristics to behavioral intention to use, but also offer strong implications for practitioners who would like to increase LMS usage and create a more effective learning environment.
Citation - WoS: 7
Citation - Scopus: 7
Exchange Rates and Firm Survival: an Examination With Turkish Firm-Level Data
(Elsevier, 2016) Toraganlı, Nazlı; Yazgan, Mustafa Ege
Micro-level empirical research has begun to obtain important results on the effects of currency variations on firms’ survival. The literature has, however, lacked a detailed analysis of the effects of exchange rates on firms’ survival behavior in emerging markets due to a scarcity of firm-level information. Using a firm-level dataset, we investigate the impact of currency appreciation on the survival behavior of Turkish firms in the manufacturing industries for 2002–2009. Our results suggest that real exchange rate appreciation decreases the probability of survival in the manufacturing industries. We also find that high-productivity firms have a higher probability of survival than low- productivity firms following an appreciation of the exchange rate. Our findings indicate that the negative effect of a 1% real appreciation of the domestic currency on the survival probability of a given firm ranges from 4.5 to 9%, providing evidence for the vulnerability of developing countries to exchange rate movements. This evidence indicates that, especially for emerging market economies, economic events and policies leading to an appreciation in the domestic currency should be managed cautiously.