Time-Varying Structure of the Optimal Hedge Ratio for Emerging Markets

Emerging markets are more exposed to risk than developed markets. Therefore, they require risk management using futures market instruments. This study aims to determine the hedging effectiveness of the spot index market risks in the stock index futures market in Brazil, Russia, India, South Africa, and Turkey. Measuring the hedging effectiveness level of futures markets is vital for these countries because investors must remain in the stock markets for the sustainability of the financial markets and economies. Weekly closing data for the period from January 2009 to October 2021 were analyzed via a dynamic method referred to as flexible least squares (FLS). Although the FLS results show that futures transactions provide high hedging effectiveness for all countries within the scope of this study, country-specific conditions may reduce the hedging effectiveness

The Relationship between the Exchange Rate, Interest Rate and Inflation: The Case of Turkey

The purpose of the study is to measure the effects of changes in exchange rates and interest rates on inflation and to determine which of the exchange rates or interest rates has a greater impact on inflation rate following the July 15, 2016 coup attempt in Turkey. Our expectation is that similar to most authors is to find that there is a long-term relationship between the inflation rates and both the exchange rate and interest rates and that the effect of the exchange rate on the Producer Price Index (PPI) is greater than that of the interest rates. Moreover, we expect to find a unidirectional causality relationship between the Interest Rate of Commercial Banks Credit (IRBC), Over Night Interest Rate (O/N) and United States Dollar (USD) and the PPI, but not between the IRBC, O/N, USD and the Consumer Price Index (CPI).JEL Codes - F31; O24; E4; E31; E43; P24; P4

How Digital Banking Affects Greenhouse Gas Emissions in Turkey? An Empirical Investigation

This paper investigates the impact of digital banking on greenhouse gas emissions in a case of developing economy, Turkey. Digital banking means more technological innovations in banking transactions. If banking transactions can be made in digital rather than physical environments, environmental effects are expected. We assume the environmental effect is positive, so the examination of this relationship is quite important. Technological innovations mean an increase in cost of digital banking transactions in the short run but in the long run this cost-increased effect is expected to turn opposite by an increase of active users in digital banking. We analyse the long-run relationship for the period between 2011/1 and 2019/4 by employing the Autoregressive Distributed Lag (ARDL) model. The results show that the increase in digital banking transactions have a positive and statistically significant effect on greenhouse gas emissions in Turkey. The findings reveal the positive trend in increasing transactions in digital banking in Turkey

The relationship between the exchange rate, interest rate, and inflation : the case of Turkey

The purpose of the study is to measure the effects of changes in exchange rates and interest rates on inflation and to determine which of the exchange rates or interest rates has a greater impact on inflation rate following the July 15, 2016 coup attempt in Turkey. Our expectation is that similar to most authors is to find that there is a long-term relationship between the inflation rates and both the exchange rate and interest rates and that the effect of the exchange rate on the Producer Price Index (PPI) is greater than that of the interest rates. Moreover, we expect to find a unidirectional causality relationship between the Interest Rate of Commercial Banks Credit (IRBC), Over Night Interest Rate (O/N) and United States Dollar (USD) and the PPI, but not between the IRBC, O/N, USD and the Consumer Price Index (CPI).peer-reviewe

Charakter wzrostu gruczolaków przysadki typu prolactinoma zależy od stężenia prolaktyny i płci pacjentów, ale nie od wartości wskaźnika Ki-67

Introduction: The objective of this study was to investigate the effects of some clinical and pathological features of prolactinomas on tumour behaviour.Material and methods: The study included 113 patients with prolactinoma (27 male, 86 female), with a mean age at diagnosis of 34.4 ± 10.0 years (40.3 ± 12.6 in males, 32.6 ± 8.3 in females). Patients were grouped as invasive or non-invasive according to radiological imaging findings. Ki-67 levels were evaluated if possible.Results: The mean adenoma size (longest dimension) was 38.6 ± 21.6 mm and 10.8 ± 9.4 mm in male and female patients. Pre-treatment serum levels of prolactin were defined as mean 1,926 ± 6,662 ng/mL in all, 124.8 ± 63.4 and 4,675 ± 10,049 ng/mL in the noninvasive and invasive groups (p < 0.05). A positive correlation was found between the serum levels of prolactin and tumour size. The rate of patients with Ki-67 ≥ 0.03 was 37.5% and 47.8% in the noninvasive and invasive groups. The reduction rates were 60.8% and 80.4% in tumour sizes and 81.1% and 93.8% in prolactin level in the noninvasive and invasive groups, respectively, (p < 0.05).Conclusions: We found a strong correlation between prolactin levels and invasiveness in male patients compared to females. Ki-67 index was not found to have a place in defining the prognosis.Wstęp: Celem badania była analiza zależności pomiędzy wybranymi danymi klinicznymi i cechami patomorfologicznymi a przebiegiem klinicznym u pacjentów z gruczolakiem przysadki wydzielającym prolaktynę (prolactinoma)/lub z gruczolakiem prolaktynowym przysadki.Materiał i metody: Do badania włączono 113 pacjentów, u których rozpoznano guzy typu prolactinoma (27 mężczyzn, 86 kobiet). Średni wiek pacjentów w momencie rozpoznania wynosił 34,4 ± 10,0 lat (40,3 ± 12,6 u mężczyzn, 32,6 ± 8,3 u kobiet). Na podstawie badań obrazowych/badań radiologicznych guzów pacjentów podzielono na dwie grupy — z gruczolakami inwazyjnymi i gruczolakami nieinwazyjnymi. Wskaźnik Ki-67 oceniono w tych preparatch, gdzie było to możliwe.Wyniki: Średni wymiar gruczolaka (mierzony według najdłuższej osi) wyniósł 38,6 ± 21,6 mm u mężczyzn i 10,8 ± 9,4 mm u kobiet. Średnie stężenie prolaktyny w surowicy przed leczeniem wynosiło 1926 ± 6662 ng/ml w całej grupie badanej, 124,8 ± 63,4 w grupie guzów nienaciekających i 4675 ± 10049 ng/ml w przypadku guzów naciekających (p < 0,05). Stwierdzono istnienie dodatniej zależności pomiędzy stężeniem prolaktyny w surowicy i wymiarem guza. Odsetki pacjentów, u których wartość wskaźnika Ki-67 była duża (≥ 0,03) wyniosły odpowiednio 37,5% w grupie guzów nienaciekających i 47,8% w grupie guzów naciekających. W grupie nowotworów nienaciekających zmniejszenie wymiarów gruczolaka nastąpiło u 60,8% a zmniejszenie stężenia prolaktyny u 81,1% pacjentów, natomiast w grupie guzów naciekających odpowiednie wartości wyniosły 80,4% i 93,8% (p < 0,05).Wnioski: U mężczyzn stwierdzono istnienie wyraźnej zależności pomiędzy stężeniem prolaktyny w surowicy a charakterem naciekającym guza, czego nie wykazano u kobiet. Wskaźnik Ki-67 nie miał związku z charakterem wzrostu guza

Sovereign Credit Default Swap Market Volatility in BRICS Countries Before and During the COVID-19 Pandemic

SCDS (Sovereign Credit Default Swaps) are becoming more widely used as a country risk indicator after 2008 and stand out for providing real-time information rather than periodic reporting. The COVID-19 pandemic has led to economic disruptions and a decline in international trade. Understanding how the Pandemic affects SCDS return volatility in emerging economies like BRICS forms the motivation for our research. With this study, we aim to determine the impact of the COVID-19 Pandemic on SCDS return volatility in Brazil, Russia, India, China and South Africa, known as the BRICS countries. We used the Exponential Generalized Autoregressive Conditional Heteroskedasticity (EGARCH) model to analyze the data, which consisted of the daily closing price data for SCDS. The date of the first COVID-19 case in each country has been taken as the beginning of the COVID-19 Pandemic in each country. The results of the estimated GARCH models show that the volatility processes of the SCDS return series differ between periods. EGARCH model results indicate that shocks created by news in these countries during the Pandemic have a small and persistent effect on Brazil and Russia's SCDS return volatility, while they have a large and enduring effect on China and South Africa's SCDS return volatility. The findings will guide policymakers and portfolio managers in determining risk management models

The impact of ESG scores on bank market value? evidence from the U.S. banking industry

Although there is a large volume of literature on the relationship between Environmental, Social and Governance (ESG) and firm performance, only a limited number of studies have focused on the banking sector. In addition, most of them used linear models. Therefore, in this study, we examined the impact of ESG and ESG pillar scores (environmental, social, and governance) on the market value of U.S. commercial banks by using linear and non-linear panel regression models over the period of 2016–2020. Moreover, we used the market value as a bank value indicator and included the effect of COVID-19. Results show an inverted U-shaped relationship between market value and ESG and The Social Pillar Score (SPS) and a U-shaped relationship between market value and The Environment Pillar Score (EPS). Findings from this study are important indicators for investment managers and policymakers who want to maximise bank market value while complying with ESG standards.peer-reviewe

The dynamic connectedness between risk and return in the Fintech market of India : evidence using the GARCH-M approach

Fintech allows investors to explore previously unavailable investment opportunities; it provides new return opportunities while also introducing new risks. The aim of this study is to investigate the relationship between risk and return in the fintech industry in the Indian stock market. This article is based on market-based research that focuses on demonstrating the volatility in the fintech market’s prices and demystifying the opportunities. Secondary data were collected from the Bombay Stock Exchange’s official fintech industry website from January 2017 to July 2022 to determine whether there is any dynamic link between risk and return in the Indian fintech market. The variance-based Mean-GARCH (GARCH-M) model was used to determine whether there is a dynamic link between risk and return in the Indian fintech market. The findings emphasize the importance of taking the risk of investing in India’s fintech industry. The implications for stock investors’ and fund managers’ portfolio composition and holding periods of equities or market exposure are significant. Finally, depending on their investment horizons, the Indian fintech industry may yield significant profits for risk-taking individuals.peer-reviewe

Turner syndrome and associated problems in turkish children: A multicenter study

Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology

The Contribution Of The Futures Trading On The Underlying Stock In Turkish Derivatives Exchange To The Efficiency Of Cash Market: An Application On Ise30 Index

4 Şubat 2005 tarihinde İzmir’de açılan Vadeli İşlem ve Opsiyon Borsası’nda (VOB) İstanbul Menkul Kıymetler Borsası’ndaki (İMKB) hisse senetleri 30 endeksi üzerine futures işlemler yapılmaya başlanmıştır. Çalışmada futures işlemlerin spot piyasa etkinliği üzerindeki etkisi, rassal yürüyüş modeli test edilerek araştırılmıştır. Rassal Yürüyüş modelinin uygulaması korelogram testi ve birim kök testi ile yapılmıştır. İnceleme kapsamına alınan İMKB30 günlük kapanış fiyatları 1 Ocak 2003 - 1 Şubat 2005 ve 4 Şubat 2005 - 30 Nisan 2007 olarak iki döneme ayrılarak analiz edilmiştir. Korelogram testi ve birim kök testi sonuçları İMKB30 endeksinin VOB’da futures işlemlere geçiş öncesinde ve sonrasında zayıf formda etkin olduğunu göstermiştir. Futures piyasa ile spot piyasa arasında kısa ve uzun dönem ilişkisi olup olmadığını görmek için Engle-Granger eşbütünleşme testi uygulanmış ve hata düzeltme modeli oluşturularak iki piyasa arasındaki nedensellik araştırılmıştır. VOB30 endeksiyle İMKB30 endeksleri arasında uzun ve kısa dönemli bir ilişki görülmüştür. Neden sonuç ilişkisinde VOB30 endeksinin İMKB30 endeksinin nedeni olması beklenirken tersine, İMKB30 endeksinin VOB30 endeksinin nedeni olduğu görülmüştür. Sonuç olarak, VOB30 endeksinin İMKB30 endeksine etki etmediği, spot piyasa etkinliği üzerinde olumlu katkı yapamadığı bulgusu elde edilmiştir.The futures trading has been started on the underlying Istanbul Stock Exchange (ISE) 30 index in Turkish Derivatives Exchange (TURKDEX) which is found on the 4’th February 2005 in İzmir. In this study, the effect of futures trading on cash market efficiency is investigated by using Random Walk Model. The practice of Random Walk Model has been carried out with the help of correlogram test and unit root test. Daily closed prices of ISE 30 index is analyzed between two period as on 1 ’ st January 2003 - 1 ’ st February 2005 and on 4’th February 2005 - 30’th May 2007. The results of correlogram test and unit root test have been denoted that ISE 30 index is efficient in the weak form before and after futures trading in TURKDEX. In order to see whether there is a short term and a along term relationships between the futures and the cash market, the Engle-Granger co-integration test has been applied, error correction model has been found and the causality between the two markets is searched. Not only a long term but also a short term relationship between the futures index and the cash index is found out. While the futures index is expected to cause the cash index; Its observed that the cash index caused the futures index. As a result, it has been found out that the futures index doesn’t have a positive effect on the efficiency of the cash market