Browsing by Author "Polat, Ali Yavuz"

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Citation - Scopus: 9
Adjustment Speed of Debt Maturity: Evidence From Financial Crises in East Asia
(Bank Indonesia Institute, 2021) Tekin, Hasan; Polat, Ali Yavuz; 01. Abdullah Gül University
We investigate the change in adjustment speed of debt maturity for East Asian firms between 1990 and 2017 by including two exogenous shocks: the Asian Financial Crisis 1997-1998 (AFC) and the Global Financial Crisis 2007-2009 (GFC). We employ the least square dummy variable correction and find that East Asian firms have a slower adjustment of long-term debt over time. Besides, the decrease in adjustment speed of long-term debt after the GFC is more compared to the decrease after the AFC. Further analysis shows the optimal debt maturity differs across countries and industries. Another important implication of our results is that firms in high governance countries are more likely to close the gap between the actual and target debt maturity in time. Overall, debt holders and investors should consider financial uncertainties. © 2025 Elsevier B.V., All rights reserved.
Agency Theory: A Review in Finance
(2020) Polat, Ali Yavuz; Tekin, Hasan; 01. Abdullah Gül University
Temsil ve risk paylaşımı problemleri büyük firmalarda sahiplik ve kontrolün ayrılmış olmasından dolayı, müvekkil (sahipler) ve vekil (yöneticiler) arasında çıkar çatışması olduğunda ortaya çıkmaktadır. Bu problemler temel olarak bilgi asimetrisinden kaynaklanmaktadır. Bu da müvekkil için vekalet maliyeti ortaya çıkarmaktadır. Halihazırdaki önemli teorilerden biri olan Vekil Teorisi vekalet ilişkilerindeki maliyetleri minimize etmeye odaklanmaktadır. Bu çalışma müvekkil-vekil ilişkilerini daha iyi anlamak için, kurumsal finans alanındaki hissedar-yönetici ve tahvil sahibi-hissedar ilişkilerine odaklanarak, müvekkil-vekil ilişkilerini kritik bir şekilde değerlendirmektedir.
Citation - WoS: 8
Citation - Scopus: 10
The Ascent of Geopolitics: Scientometric Analysis and Ramifications of Geopolitical Risk
(Taylor & Francis Ltd, 2023) Aysan, Ahmet Faruk; Polat, Ali Yavuz; Tekin, Hasan; Tunali, Ahmet Semih; 01. Abdullah Gül University
In recent years, geopolitical risk (GPR) has been a crucial factor in investment decisions and stock markets. Therefore, we explore the research on the GPR by employing bibliometric and scientometric analytical techniques. We find 366 scientific contributions in December 2021 from the Scopus database by searching 'Geopolitical risk' in abstracts, keywords, and titles. Our findings show that GPR research has gained momentum in the last three years. Specifically, the journal Defence and Peace Economics has one of the highest numbers of research and citation on GPR. Authors in Asia also dominate the GPR literature. Overall, this study contributes to the literature by presenting the existing research that may give new insights for prospective studies in GPR.
Citation - WoS: 16
Citation - Scopus: 18
Assessing the Impact of COVID-19 Pandemic in Turkey With a Novel Economic Uncertainty Index
(Emerald Group Publishing Ltd, 2021) Mugaloglu, Erhan; Polat, Ali Yavuz; Tekin, Hasan; Kilic, Edanur; 0000-0001-5362-6259; AGÜ, Yönetim Bilimleri Fakültesi, Ekonomi Bölümü; Mugaloglu, Erhan; 01. Abdullah Gül University
Purpose This study aims to measure economic uncertainty in Turkey by a novel economic uncertainty index (EUI) employing principal component analysis (PCA). We assess the impact of Covid-19 pandemic in Turkey with our constructed uncertainty index. Design/methodology/approach In order to obtain the EUI, this study employs a dimension reduction method of PCA using 14 macroeconomic indicators that spans from January 2011 to July 2020. The first principal component is picked as a proxy for the economic uncertainty in Turkey which explains 52% of total variation in entire sample. In the second part of our analysis, with our constructed EUI we conduct a structural vector autoregressions (SVAR) analysis simulating the Covid-19-induced uncertainty shock to the real economy. Findings Our EUI sensitively detects important economic/political events in Turkey as well as Covid-19-induced uncertainty rising to extremely high levels during the outbreak. Our SVAR results imply a significant decline in economic activity and in the sub-indices as well. Namely, industrial production drops immediately by 8.2% and cumulative loss over 8 months will be 15% on average. The losses in the capital and intermediate goods are estimated to be 18 and 25% respectively. Forecast error variance decomposition results imply that uncertainty shocks preserve its explanatory power in the long run, and intermediate goods production is more vulnerable to uncertainty shocks than overall industrial production and capital goods production. Practical implications The results indicate that monetary and fiscal policy should aim to decrease uncertainty during Covid-19. Moreover, since investment expenditures are affected severely during the outbreak, policymakers should impose investment subsidies. Originality/value This is the first study constructing a novel EUI which sensitively captures the critical economic/political events in Turkey. Moreover, we assess the impact of Covid-19-driven uncertainty on Turkish Economy with a SVAR model.
Citation - WoS: 3
Citation - Scopus: 8
Bitcoin-Specific Fear Sentiment Matters in the COVID-19 Outbreak
(Emerald Group Publishing Ltd, 2022) Polat, Ali Yavuz; Aysan, Ahmet Faruk; Tekin, Hasan; Tunali, Ahmet Semih; 01. Abdullah Gül University
Purpose This study aims to investigate the effect of fear sentiment with a novel data set on Bitcoin's (BTC) return, volatility and transaction volume. The authors divide the sample into two subperiods to capture the changing dynamics during the COVID-19 pandemic. Design/methodology/approach The authors retrieve the novel fear sentiment data from Thomson Reuters MarketPsych Indices (TRMI). The authors denote the subperiods as pre- and post-COVID-19 considering January 13, 2020, when the first COVID-19 confirmed case was reported outside China. The authors use bivariate vector autoregressive models given below with lag-length k, to investigate the dynamics between BTC variables and fear sentiment. Findings BTC market measures have dissimilar dynamics before and after the Coronavirus outbreak. The results reveal that due to the excessive uncertainty led by the outbreak, an increase in fear sentiment negatively affects the BTC returns more persistently and significantly. For the post-COVID-19 period, an increase in fear also results in more fluctuations in transaction volume while its initial and cumulative effects are both negative. Due to extreme uncertainty caused by the COVID-19 pandemic, investors may trade more aggressively in the initial phases of the shock. Practical implications The authors are convinced that the results in this paper have more far-reaching implications for other markets regulated by the states. BTC provides a natural benchmark to understand how fear sentiment drives and impacts the markets isolated from any interventions. Hence, the results show that in the absence of regulatory frameworks, market dynamics are likely to be more volatile and the fear sentiment has more persistent impacts. The authors also highlight the importance of using micro, asset-specific sentiment measures to capture market dynamics better. Originality/value BTC is not associated with any regulatory authority and is not produced by the governments and central banks. COVID-19 as a natural experiment provides an opportunity to explore the pure effects of market sentiment on BTC considering its decentralized and unregulated features. The paper has two main contributions. First, the authors use BTC-specific fear sentiment novel data set of TRMI instead of more general market sentiments used in the existing studies. Next, this is the first study to examine the association between fear and BTC before and after COVID-19.
Covid-19 Salgınının Ekonomik Etkisinin Sektörel Bazlı ve Genel Belirsizlik Endeksleriyle İncelenmesi ve Sektörel Acil Önlem Önerileri
(TUBİTAK, 2020) Polat, Ali Yavuz; Muğaloğlu, Erhan; Doğan, Eyüp; Tekin, Hasan; 0000-0001-5647-5310; 0000-0001-5362-6259; 0000-0003-0476-5177; AGÜ, Yönetim Bilimleri Fakültesi, Ekonomi Bölümü; Polat, Ali Yavuz; Muğaloğlu, Erhan; Dogan, Eyup; Tekin, Hasan; 01. Abdullah Gül University; 03.02. Ekonomi; 03. Yönetim Bilimleri Fakültesi
Koronavirüs (Covid-19) salgını dünyada modern zamanlarda görülen en büyük sağlık_x000D_ krizlerinden birisidir. Ancak salgın sadece bir sağlık krizi olarak kalmamış tüm dünyayı_x000D_ etkileyen küresel, ekonomik ve sosyal krize dönüşmüştür. Birçok sektörde üretim durmuş, gelir_x000D_ etkisi ile tüketim ciddi ölçüde azalmıştır. Covid-19 salgınının oluşturduğu ekonomik kriz son 40_x000D_ yılda gerçekleşmiş ekonomik krizler ve felaketlerden çok daha büyüktür. Pandeminin sebep_x000D_ olduğu/olacağı küresel krizin daha önceki küresel krizlere göre çok daha derin ve kalıcı olacağı_x000D_ tahmin edilmektedir. Dünya ekonomisi 2020’de %4,0 küçülmüştür ki bu oran küresel finansal_x000D_ krizdeki daralmanın yaklaşık iki katıdır (Oxford Economics, 2020)._x000D_ Salgının oluşturacağı şokların etkisi ve süresi net olarak bilinemediği ve tahmin_x000D_ edilemediği için ekonomilerde yüksek oranda belirsizliğe yol açmıştır (Ludvigson et al. 2020)._x000D_ Bilindiği üzere belirsizlik hem tüketim hem de yatırımların ertelenmesine ve dolayısıyla_x000D_ ekonomik daralmaya sebep olur (Bloom, 2009). Firmalar açısından bakıldığında salgının ne_x000D_ kadar süreceği, tedarik zincirlerinin onarılıp onarılamayacağı halen net değildir. Ayrıca_x000D_ bireylerin gelirleri ekonomik aktivitenin yavaşlaması sonucunda azaldığı gibi salgının_x000D_ oluşturduğu belirsizlik ortamı bireylerin harcamalarını daha da kısmalarına sebep olmaktadır._x000D_ Bu yüzden belirsizlik seviyesinin hassas bir gösterge ile ölçülmesi önem arz etmektedir._x000D_ Bu proje ile sektörel bazlı (hizmet, perakende ve inşaat) ve genel belirsizlik endeksleri_x000D_ (ekonomik ve reel) oluşturulmuştur. Bu endeksler Türkiye’deki önemli politik ve ekonomik_x000D_ olaylarda ani artışlar göstermektedir. Yani oluşturulan endeksler, reel aktiviteyi önemli ölçüde_x000D_ etkileyen belirsizlik artışlarını hassas olarak ölçebilmektedir._x000D_ Projenin ikinci kısmında Covid-19 salgının reel ekonomi üzerindeki etkisi belirsizlik_x000D_ endeksleri üzerinden analiz edilmiştir. Oluşturulan yapısal vektör oto regresyon (SVAR)_x000D_ modelleri ile belirsizliğin hem toplam sanayi üretimine hem de her sektördeki üretimi üzerinde_x000D_ nasıl bir etki oluşturduğu gösterilmiş ve tartışılmıştır. Sonuçlar göstermektedir ki, belirsizlikteki_x000D_ bir artış reel aktiviteyi düşürmektedir. Bu sonuç teorik olarak belirsizliğin ekonomiyi_x000D_ yavaşlatacağı argümanını ampirik olarak desteklemektedir. Covid-19’un oluşturduğu_x000D_ belirsizlik, tüm zamanlar içinde en yüksek ve ani belirsizlik artışına sebep olmuştur ve reel_x000D_ aktivite üzerinde şiddetli bir negatif etkisi olmuştur._x000D_ Projemizde oluşturduğumuz belirsizlik endeksleri ve analizler sayesinde spesifik mali_x000D_ yardım paketlerinin hangi sektörlerde nasıl bir etki oluşturulabileceği tahmin edilebilir. Ayrıca_x000D_ elde edilen endeksler, politika yapımında önemli bir gösterge araç olarak kullanılabilir._x000D_ Oluşturduğumuz sektörel ve genel belirsizlik endeksleri ilerideki projeler ve politikalar için de_x000D_ önemli bir kaynak teşkil edecektir. Daha ayrıntılı sektörel politikalar geliştirebilmek, salgın_x000D_ geçtikten sonra Türkiye’nin jeopolitik avantajını kullanarak üretim merkezi olabilmesi ve tedarik_x000D_ zincirinde aktarma merkezi olabilmesi için belirsizliğin oluşturduğumuz endeksler gibi hassas_x000D_ göstergeler ile ölçümlenmesi önemli bir gerekliliktir
Citation - WoS: 7
Citation - Scopus: 23
Do Market Differences Matter on Dividend Policy?
(Elsevier, 2021) Tekin, Hasan; Polat, Ali Yavuz; 01. Abdullah Gül University
We investigate the dividend policies of firms in the United Kingdom to understand whether firms in different markets use dividends as a signaling or disciplining device. The sample consists of 1247 firms from the highly regulated Main Market (MAIN) and relatively unregulated Alternative Investment Market (AIM) for the period 2002-2017. We find that firms in AIM pay lower dividends than their MAIN counterparts. However, during turbulence, AIM firms decrease dividends lower than MAIN firms. In line with the signaling hypothesis, AIM firms with increased profitability are more likely to increase dividends. These results suggest that AIM firms depend more on the signaling feature of the dividends, whereas MAIN firms use dividends as a disciplining device to limit managerial discretion. Specifically, we find that AIM firms facing bigger agency problems pay lower dividends compared to other AIM firms, in line with the outcome view of agency theory. Copyright (C) 2020, Borsa Istanbul Anonim Sirketi. Production and hosting by Elsevier B.V.
Ekonomik Belirsizlik ve COVID-19 Salgınının Türkiye'de Eğitim Durumuna Göre İşgücüne Etkisinin Analizi: Svar Yaklaşımı
(Abdullah Gül Üniversitesi, Sosyal Bilimleri Enstitüsü, 2022) Kılıç, Edanur; Kılıç, Edanur; Polat, Ali Yavuz; AGÜ, Sosyal Bilimler Enstitüsü, Veri Bilimi Anabilim Dalı; 01. Abdullah Gül University
The economic downturns affect the fluctuations in the labor force participation rate. The pandemic brings about many changes in different areas and the labor force participation rate is one of them. This study analyses the impact of economic uncertainty innovations on the labor force participation rate in Turkey for the period January 2011 to November 2019. We also consider different educational attainment, which consists of five categories, because finding a job gets hard in recent years and there is no academic study on whether education level matters or not in Turkey. We obtain an economic uncertainty index to analyze the effect of Covid-19 and generate multivariate models (SVAR) to determine the relationship between uncertainty and labor force participation rate. We examine labor force statistics at different educational attainment levels to understand whether there are any changes or not. Thus, the main research question is that 'How is the impact of uncertainty shocks on labor force participation rate in different levels of education in Turkey?'. The results show that the labor force participation rate decreases, while the unemployment rate increases in such an economic downturn.
The Global Financial Crisis and Capital Structure Decisions of Turkish SMEs: A Review
(2020) Tekin, Hasan; Polat, Ali Yavuz; 01. Abdullah Gül University
Küresel finansal krizle birlikte belirsizlikler artmış, böylece, sermaye yapısı kararları Türkfirmaları, özellikle küçük ve orta ölçekli (KOBİ) firmalar için çok önemli hâle gelmiştir. KOBİ’ler dahayüksek bilgi asimetrisi, işlem maliyetleri ve riskle karşı karşıya olduğundan, finansal piyasalardaki kargaşa sırasında finansmana erişimde daha fazla güçlükle karşılaşırlar. Bu incelemede, Türk firmalarının sermaye yapısı kararlarından elde edilen bulguları karşılaştırmalı olarak analiz ediyoruz.Tahmin edilebileceği gibi, ciddi kriz koşullarında KOBİ’lerin Borsa İstanbul’da listelenen firmalardandaha fazla önlem almasını bekliyoruz.
Citation - WoS: 2
Citation - Scopus: 2
Investor Bias, Risk and Price Volatility
(Emerald Group Publishing Ltd, 2023) Polat, Ali Yavuz; 01. Abdullah Gül University
PurposeThis study proposes a framework based on salience theory and shows that focusing on one type of risk (idiosyncratic or systemic) can explain overpricing of securities ex ante, and resales at low prices during crisis periods.Design/methodology/approachThe author consider an overlapping generations (OLG) model where each generation lives for two periods and there is no population growth. Agents (investors) start their lives with an endowment W > 0 and have mean-variance utility. They invest their endowment when young and consume when old. Each period, the young investors optimally choose their portfolio from different risky assets acquired from the old generation, all assumed to be in fixed supply.FindingsThe author show that investor salience bias can explain excess volatility of asset prices and the resulting fire-sales in periods of financial turmoil. A change in salience - from one component (idiosyncratic) to the other (systemic) - will generate excess volatility. Interestingly, higher risk aversion generally exacerbates the excess volatility of prices. Moreover, the model predicts that if a big systemic shock hits the financial system, due to salience bias the price of systemic assets falls sharply. This relates to the observed fire-sales of assets during the global financial crisis.Practical implicationsThe proposed model and results suggest that there may be a scope for intervention in financial markets during turbulences. In terms of ex ante policies the study suggests that investors and regulator should use better risk assessment technologies.Originality/valueThis is the first study constructing a tractable model based on the argument that investor salience may exacerbate the excess volatility of prices during financial downturns. The author relate salience to two types of risk; idiosyncratic and systemic and assume that investors' risk perception is biased towards the type of risk that is currently salient based on prior beliefs or past data. The author show that the diversification fallacy of the precrisis period, where seemingly safe assets were overpriced, can be explained by agents overweighing idiosyncratic risk and ignoring systemic risk.
Citation - WoS: 6
Citation - Scopus: 17
Is Leverage a Substitute or Outcome for Governance? Evidence From Financial Crises
(Emerald Group Publishing Ltd, 2021) Tekin, Hasan; Polat, Ali Yavuz; 0000-0001-5647-5310; AGÜ, Yönetim Bilimleri Fakültesi, Ekonomi Bölümü; Polat, Ali Yavuz; 01. Abdullah Gül University
Purpose The authors investigate the impact of governance on the leverage of East Asian firms in the financial crisis context, in order to understand the puzzle whether debt acts as a substitute for governance or an outcome of the governance mechanism. Design/methodology/approach The authors use 86,030 firm-years and the country-level governance data from eight East Asian countries over the period 1996-2017. The authors employ the fixed effects (FE) model, in the main analysis and the weighted least squares model, as a robustness check in order to compare the two competing hypotheses of agency theory, substitute and outcome models. Findings The authors' results show that debt acts as a substitute for governance before the GFC, but during and after the GFC the picture changes. Namely, debt acts as an outcome of the governance mechanism during the GFC and its aftermath. Since during financial downturns both agency costs increase, and information asymmetry widens, firms in poor-governed countries may be reluctant to increase their leverage in order not to face financial distress and additional restrictions. Thus, the results imply that the use of debt as a tool to mitigate agency conflicts and a substitute for governance strongly depends on the environment that the firms operate and the general macroeconomic conditions, such as facing a financial crisis or not. Research limitations/implications This study provides an interesting case of the firms' capacity to raise money during a crisis and that governance plays an important role in borrowing activities of firms. This will undoubtedly help motivating owners and policymakers for improving governance. The authors' findings may be useful for policymakers to develop policies considering the adverse effects caused by exogenous shocks. This is crucial because the severity of GFC as a shock seems to change the macro and institutional environment that firms operate. While the authors properly address the research hypotheses using country governance data, future research may employ corporate governance data to attain firm-level results by testing two competing hypotheses. Originality/value There are several important areas where this study makes original contributions. First, while Tsoy and Heshmati (2019) focus on the dynamics of capital structure for only Korean firms, the authors extend the sample including eight East Asian countries considering the impact of country governance on capital structure policy. Specifically, this study is the first in using the robust country governance data, which differs by country and year, in the crisis context. Next, the authors investigate both the AFC and GFC to compare whether these two crises have different effects on capital structure policy of East Asian firms. Finally, the authors aim to understand whether leverage is used as a substitute for governance or an outcome of governance mechanism considering recessions.
Citation - WoS: 6
Citation - Scopus: 14
Is Saving Vital? Evidence from the Financial Crisis
(Univ Oviedo, 2020) Tekin, Hasan; Polat, Ali Yavuz; 01. Abdullah Gül University
We use a sample of 8,561 firm-years from the highly regulated Main Market (MAIN) and relatively unregulated Alternative Investment Market (AIM) in the United Kingdom to analyse the impact of financial restrictions on optimal cash holdings in the context of financial crises. Employing system generalised methods of moments, we find that AIM firms have a faster adjustment speed of cash as confirmed by precautionary and transaction motives over 2002-2017. However, AIM firms decrease (increase) their adjustment speed of cash more than MAIN firms during (after) the financial crises.
Küresel Finansal Kriz ve Nakit Tutma Ayarlama Hızı
(2021) Polat, Ali Yavuz; Tekin, Hasan; Mugaloglu, Erhan; 01. Abdullah Gül University
Dış finansmana erişimin sınırlı olduğu zamanlarda nakit tutma stratejik bir öneme sahip olmaktadır. Likit varlıklar, özellikle dış şoklarla birlikte firmaların varlıklarını devam ettirebilmeleri için çok önemli hale gelmektedir. Öyle ki, nakit varlıkların talep fonksiyonu, doğal bir deney imkânı sunan 2008-2009 Küresel Finansal Krizine (KFK) bağlı olarak değişebilmektedir. Optimum nakit tutma teorisine dayanan bu çalışma, KFK’den önce ve sonra Borsa İstanbul (BİST)'da işlem gören finansal olmayan firmaların nakit varlıklarının ayarlama hızını 2003-2018 zaman dilimi için incelemektedir. Herhangi bir içsellik problemini azaltmak için genelleştirilmiş momentler yöntemi (GMM) kullanılmıştır. Bulgular, BİST’teki firmaların KFK sırasında kredi arzının azalması ve dış fonlama maliyetlerinin de artmasından dolayı daha fazla nakit stoku kullanmaları neticesinde, kriz ve sonrasında nakit varlıklarının ayarlama hızının arttığını göstermektedir. Genel bir sonuç olarak, firma sahipleri ve yöneticileri, krizler gibi yüksek belirsizlik ortamlarında kurumsal finansmanı etkileyen faktörleri de göz önünde bulundurarak ve nakit tutmanın maliyetini hesaba katarak, firmaları için doğru nakit tutma politikası belirlemelidirler.
Küresel Finansal Krizin Araştırma-geliştirme Harcamaları Ayarlama Hızı Üzerindeki Etkisi
(2021) Polat, Ali Yavuz; Tekin, Hasan; 01. Abdullah Gül University
Amaç: Verimlilik artışını uzun vadede etkileyen Araştırma-Geliştirme (Ar-Ge) yatırımları hem şirketler hem\rde ülkeler düzeyinde son derece önemlidir. Küresel Finansal Kriz gibi ekonomik belirsizliğin arttığı bir\rdönemde firmaların yatırım kararları da bu belirsizlikten etkilenmektedir. Bu çalışmanın amacı, 2008-2009\rKüresel Finansal Krizinin Borsa İstanbul’da listelenen şirketlerin, Ar-Ge harcamalarının ayarlama hızlarını\rnasıl değiştirdiğini analiz etmektir.\rYöntem: Veri seti Thomson Reuters Datastream veri tabanından yıllık olarak çekilmiştir. Firma düzeyinde\roluşturulan panel veri 908 şirket-yılını kapsamaktadır. Geliştirilmiş Momentler Metodu (GMM) yardımıyla\riçsellik problemi en aza indirgenmeye çalışılmıştır.\rBulgular: 2003-2018 yılları için şirketlerin Ar-Ge harcamaları ayarlama hızlarının nispeten yavaş olduğu\rgörülmüştür. Bununla birlikte, şirketler Küresel Finansal Kriz sonrasında Ar-Ge harcamaları ayarlama\rhızlarını artırmışlardır. Genel olarak, zaman içinde Ar-Ge harcamalarını optimal bir düzeye getirmek isteyen\rşirket sahipleri ve yöneticileri ayarlama maliyetlerini ve belirsizliğin arttığı finansal krizleri göz önünde\rbulundurmalıdırlar.\rÖzgünlük: Bu çalışma Borsa İstanbul’da listelenen şirketlerin ilk kez Ar-Ge ayarlama hızlarını hesaplayarak\rkriz dönemi gibi belirsizlik dönemini de kapsayarak literatüre katkıda bulunmaktadır.\r
Citation - Scopus: 20
Oil Price Shocks During the COVID-19 Pandemic: Evidence From United Kingdom Energy Stocks
(Asia-Pacific Applied Economics Association, 2021) Muğaloğlu, Erhan; Polat, Ali Yavuz; Tekin, Hasan; Dogan, Abdullah; 01. Abdullah Gül University
We investigate the dynamic relationship between global oil prices, the stock market, and oil and gas stock (FTSE-OG) returns in the UK through a structural vector autoregressive (VAR) framework during the COVID-19 pandemic. The structural VAR results suggest that the impact of structural shocks related to the global oil price on FTSE-OG index returns becomes less important and loses its explanatory power during the pandemic. However, stock market shocks increase their explanatory power in the variations of FTSE-OG index returns. © 2023 Elsevier B.V., All rights reserved.
Rule of Law, International Trade, and Corporate Financing Decisions in Europe: Evidence From the COVID-19 Pandemic
(IGI Global, 2022) Polat, Ali Yavuz; 01. Abdullah Gül University
This chapter investigates whether the institutional environment that the firms operate has an impact on their leverage choice. Namely, rule of law is used as an institutional variable. Considering that better implementation of rule of law impacts positively firms' export performance, total exports in each country are also used as the other main explanatory variable. The findings show that both institutional variables and exports negatively and significantly affect the leverage level. This implies that firms in favorable institutional environment tend to borrow less, which results with lower leverage. Moreover, this study finds that the COVID-19 pandemic period as an unprecedented shock to economies pushed the leverage levels higher. Regarding the implications of the findings, firms' capacity to access external finance especially during a significant crisis period depends on the institutional environment. Namely, the effective implementation of rule of law should be first priority for the policy makers. © 2023 Elsevier B.V., All rights reserved.
Citation - Scopus: 3
Subprime Mortgages and Lending Bubbles
(Bank Indonesia Institute, 2018) Polat, Ali Yavuz; 0000-0001-5647-5310; AGÜ, Yönetim Bilimleri Fakültesi, Ekonomi Bölümü; Polat, Ali Yavuz; 01. Abdullah Gül University
We consider a model with two types of households: the poor with no initial endowment and the rich with positive endowment, and two types of assets: properties in a poor area and properties in a rich area. In the model, poor agents need credit to buy an asset, whereas the rich can draw from their endowment. We show that credit-fueled housing bubbles sometimes may improve welfare, making the poorer individuals better off. More precisely, there exist two types of equilibria in both property markets: one is a bubble equilibrium, and the other is an equilibrium where asset prices are stable over time. While the poor always obtain a positive surplus in the bubble equilibrium, this is not necessarily true for the rich. Our results suggest that there may be scope for market interventions aimed at sustaining the value of assets held by credit-constrained agents after the burst of a credit bubble. © 2025 Elsevier B.V., All rights reserved.
Citation - WoS: 5
Citation - Scopus: 6
Whether and When Did Bitcoin Sentiment Matter for Investors? Before and During the COVID-19 Pandemic
(Springer, 2023) Aysan, Ahmet Faruk; Mugaloglu, Erhan; Polat, Ali Yavuz; Tekin, Hasan; 01. Abdullah Gül University
Using a wavelet coherence approach, this study investigates the relationship between Bitcoin return and Bitcoin-specific sentiment from January 1, 2016 to June 30, 2021, covering the COVID-19 pandemic period. The results reveal that before the pandemic, sentiment positively drove prices, especially for relatively higher frequencies (2-18 weeks). During the pandemic, the relationship was still positive, but interestingly, the lead-lag relationship disappeared. Employing partial wavelet tools, we factor out the number of COVID-19 cases and deaths and the Equity Market Volatility Infectious Disease Tracker index to observe the direct relationship between a change in sentiment and return. Our results robustly reveal that, before the pandemic, sentiment had a positive effect on return. Although positive coherence still existed during the pandemic, the lead-lag relationship disappeared again. Thus, the causal relationship that states that sentiment leads to return can only be integrated into short-term trading strategies (up to six weeks frequency).