SÜREYYA İMRE - Academia.edu (original) (raw)

Papers by SÜREYYA İMRE

Gazi iktisat ve işletme dergisi, Feb 28, 2024

The direct or indirect impact and importance of educated women on society can be understood accor... more The direct or indirect impact and importance of educated women on society can be understood according to their success in business and the values they bring to the country. It is known that the pre-modern market is subject to a patriarchal system and women in the sector mostly work in areas such as labor and cheap labor. Emotional and intellectual competencies of women are needed to develop a qualified society ahead of the times and for a sustainable life, and it is important for them to be employed. While emphasizing the importance of education, this study investigates the impact of highly educated (university and postgraduate) female workforce on sustainable growth and economy: women on themselves, their environment and their country. Developing or developing countries were selected without a specific country group through World Bank Data and UNDP centers. The values of women's literacy rate, unemployment and highly educated workforce data between 2010 and 2018 were taken. Cluster analysis was performed using the Python language. Countries are divided into 3 groups as a result of applying the K-means method in terms of the GDP impact of the highly educated female workforce. Iran is in the first cluster, where the unemployment rate of the highly educated workforce is lower than the average, Egypt and Bangladesh are in the second cluster, where employment is gradually decreasing, and Turkey, Brazil, Indonesia, South Africa and Mexico are in the third cluster, where the literacy rate and labor force averages are above a certain level and close to each other has received. The sustainable growth impact of the advanced educated female workforce is discussed in the conclusion.

DergiPark (Istanbul University), Apr 10, 2023

Ekonomi bilimleri dergisi, Jan 13, 2024

Journal of business, economics and finance, Dec 30, 2023

Yönetim ve ekonomi araştırmaları dergisi, Nov 26, 2023

DergiPark (Istanbul University), Apr 20, 2023

The increase in the human capital of countriesensures their growthand development by increasing t... more The increase in the human capital of countriesensures their growthand development by increasing the capital investmentrates by ensuring the effective and efficientuse of production factors. The fact that women, who make up half of the society, are not included in economic activities is an important disruption that affects social welfare by disrupting the grow than development of countries. In thisstudy, which aims to test there lationship between the female labor force participation rate and economic growth, Turkey, which has experienced a growth that does not create employment, is taken into consideration, and the female labor force participation rate (15 yearsandover, annual) data obtained from the UNDP for the period 1990-2021, and the World Bank's data. GDP growth (% perannum) data from according to the findings, it has been determined that the labor force participation rate of women is statistically significantand has a positive effect on economic growth. A %1 increase in women's labor force participation rate causes a %0.12 increase in growth. According to the findings obtained from the Granger Causality Test, which was applied to question the causality relationship between the variables, it reveals that there is one-waycausality from GDP to womens employment. This study is important in terms of expanding the typology as well as emphasizing the negative impact of gender-based preferences and barriers on economic growth and social welfare.

Eurasian Econometrics Statistics & Emprical Economics Journal

Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile geliş... more Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile gelişmiş ve gelişmekte olan ülkelerin borsaları arasındaki volatilite yayılımı 24.03.2015-21.04.2021 tarihlerine ait günlük veriler kullanılarak araştırılmıştır. Analizde çok değişkenli GARCH modelleri sınıfında değerlendirilen DCC-GARCH modeli kullanılmıştır. Elde edilen bulgulara göre BIST100 volatilitesi ile IDX ve MOEX volatilitesi arasında karşılıklı volatilite etkileşimi bulunamamıştır. BIST100 ile NSE30, CAC40, DAX arasında tek yönlü volatilite etkileşimi bulunurken BIST100 ile DJIA ve NIFTY50 borsaları arasında ise çift yönlü volatilite etkileşimi bulunmuştur.

DergiPark (Istanbul University), Sep 23, 2021

Bu çalışmada, popülerliği son yıllarda artan kripto paralar sınıfında değerlendirilen Bitcoin ile... more Bu çalışmada, popülerliği son yıllarda artan kripto paralar sınıfında değerlendirilen Bitcoin ile Euro getirileri arasındaki volatilite etkileşimini incelemek için 02.02.2014-28.02.2021 dönemine ait günlük veriler kullanılmıştır. Değişkenlere ait getirilerin zaman içindeki hareketini incelemek için oluşturulan grafiklerden volatilite kümelenmesi tespit edilmiş ve analiz için "Çok Değişkenli GARCH Modelleri" kullanılmıştır. Modellerden elde edilen sonuçlar karşılaştırılmış ve log-olabilirlik değeri mutlak değerce en büyük bulunan "BEKK-GARCH Modeli" uygun model kabul edilmiştir. Bulgular incelendiğinde, Euro ile Bitcoin arasında çift yönlü volatilite etkileşimi bulunmuştur. Ayrıca DCC-GARCH modeli sonuçlarına göre ise iki getiri arasında asimetri ilişkisi ve pozitif, güçlü bir dinamik korelasyon tespit edilmiştir

DergiPark (Istanbul University), Mar 9, 2022

In order to understand relationships between different currencies, Econometrics presents us a lot... more In order to understand relationships between different currencies, Econometrics presents us a lot of tools. One of these tools ARCH Models are often used by many papers. On the other side, anomalies, and volatilities are the main psychological results of financial markets. This paper, it is aimed to determine some anomalies of currencies with an ARCH model as EGARCH (p, q) model with data 03.02.2014-31.12.2020 period on Bitcoin and Euro Currency. It is made in this paper clear that financial investors behave towards financial assets within anomalies and volatilities. Therefore, it is proved that the main focal point of financial epistemology should be anomalies, so volatilities also in financial innovations.

Computers, Materials & Continua

Construction Industry operates relying on various key economic indicators. One of these indicator... more Construction Industry operates relying on various key economic indicators. One of these indicators is material prices. On the other hand, cost is a key concern in all operations of the construction industry. In the uncertain conditions, reliable cost forecasts become an important source of information. Material cost is one of the key components of the overall cost of construction. In addition, cost overrun is a common problem in the construction industry, where nine out of ten construction projects face cost overrun. In order to carry out a successful cost management strategy and prevent cost overruns, it is very important to find reliable methods for the estimation of construction material prices. Material prices have a time dependent nature. In order to increase the foreseeability of the costs of construction materials, this study focuses on estimation of construction material indices through time series analysis. Two different types of analysis are implemented for estimation of the future values of construction material indices. The first method implemented was Autoregressive Integrated Moving Average (ARIMA), which is known to be successful in estimation of time series having a linear nature. The second method implemented was Non-Linear Autoregressive Neural Network (NARNET) which is known to be successful in modeling and estimating of series with non-linear components. The results have shown that depending on the nature of the series, both these methods can successfully and accurately estimate the future values of the indices. In addition, we found out that Optimal NARNET architectures which provide better accuracy in estimation of the series can be identified/discovered as result of grid search on NARNET hyperparameters.

Construction Industry operates relying on various key economic indicators. One of these indicator... more Construction Industry operates relying on various key economic indicators. One of these indicators is material prices. On the other hand, cost is a key concern in all operations of the construction industry. In the uncertain conditions, reliable cost forecasts become an important source of information. Material cost is one of the key components of the overall cost of construction. In addition, cost overrun is a common problem in the construction industry, where nine out of ten construction projects face cost overrun. In order to carry out a successful cost management strategy and prevent cost overruns, it is very important to find reliable methods for the estimation of construction material prices. Material prices have a time dependent nature. In order to increase the foreseeability of the costs of construction materials, this study focuses on estimation of construction material indices through time series analysis. Two different types of analysis are implemented for estimation of the future values of construction material indices. The first method implemented was Autoregressive Integrated Moving Average (ARIMA), which is known to be successful in estimation of time series having a linear nature. The second method implemented was Non-Linear Autoregressive Neural Network (NARNET) which is known to be successful in modeling and estimating of series with non-linear components. The results have shown that depending on the nature of the series, both these methods can successfully and accurately estimate the future values of the indices. In addition, we found out that Optimal NARNET architectures which provide better accuracy in estimation of the series can be identified/discovered as result of grid search on NARNET hyperparameters.

Stratejik ve Sosyal Araştırmalar Dergisi

It is a well-known fact that economic freedom is one of the important stimulators of its impact o... more It is a well-known fact that economic freedom is one of the important stimulators of its impact on the level of development and welfare of a country. In this study, data from the Fragile Five Countries covering the years 1999-2018 were used to investigate the effect of the economic freedom index, which is used to determine and measure economic freedoms, on the human development index, which is used to measure human welfare. According to the results obtained, a 1% increase in the economic freedom index increases the human development index by 0.54% for India, 0.30% for Brazil, 0.61% for Turkey. For Indonesia, it decreases by 0.48%. In South Africa, however, no effect of the economic freedom index on the human development index was detected. When comments are made for all countries, the 1% increase in the economic freedom index increases the human development index by 1.84%.

Yönetim ve Ekonomi Araştırmaları Dergisi, 2021

Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisi... more Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisini ölçmek amaçlanmıştır. Bu amaçla 05.01.2015-02.07.2021 tarihlerini kapsayan ilgili BİST sektör endekslerinin günlük kapanış fiyatları kullanılmıştır. BİST sektör endekslerinde hem pandeminin etkilerini tespit etmek hem de asimetri ve kaldıraç etkisinin varlığını araştırmak amacıyla Üstel Genelleştirilmiş Otoregresif Koşullu Heterokedastisite (EGARCH) modeli kullanılmıştır. Elde edilen bulgulara göre Covid-19'un, XBLSM, XGIDA, XSGRT sektör getirileri üzerinde pozitif, XTEKS, XTRZM sektör getirileri üzerinde ise negatif bir etkisi olduğu tespit edilmiştir. Pandemi sürecinde XBLSM, XSGRT ve XGIDA getirileri artarken, XTEKS ve XTRZM getirileri azalmıştır. Aynı şekilde oynaklık üzerinde Covid-19'un etkisine bakıldığında XBLSM, XGIDA ve XSGRT sektörlerinin volatilitesi pozitif yönlü etkilenirken, XTEKS, XTRZM, XULAS sektörlerinin volatilitesi negatif yönlü etkilenmiştir.

Ekoist: Journal of Econometrics and Statistics, 2021

There are many studies in the literature on child labor. However, most of these studies are based... more There are many studies in the literature on child labor. However, most of these studies are based on statistics on children, or the factors that cause child labor are explained as economic concepts. The purpose of this study is to investigate the reasons why school-age children adopt the role of "child laborer" and determine the effects of these factors. In this context, in order to examine the factors affecting child labor in developing countries, this study has tried to determine the factors causing child labor with dynamic panel data analysis using MINT Countries data for the period of 1990-2018. The countries' development levels and poverty are closely related to child labor. For this reason, the human development index is added to the model as a dependent variable. Considering the studies in the literature, population growth, primary school enrollment rate, primary school duration, and labor force participation rate variables were added to the model as independent variables. At the end of the analysis, all variables were found to be statistically significant. The effect of population growth and the number of primary school students on the human development index was negative, while the effect of other variables was positive.

The “Sell in May” Effect: An Empirical Analysis from Turkey, Indonesia, France, and Germany , 2022

This study aims to provide empirical insight into the "Sell in May" (SIM) effect in Turkey, Indon... more This study aims to provide empirical insight into the "Sell in May" (SIM) effect in Turkey, Indonesia, France, and Germany stock exchange markets. We examined Turkey BIST All, BIST Dividend (XTM25), Indonesia IDX Composite, France CAC All (PAX), MSCI France High Dividend Yield (MSCIFRDIV), and Germany CDAX, DivDAX price indices, and individual stocks in dividend indices. Average monthly return data for January 2015 and December 2020 were used for the research. Linear, Quantile regression, and Autoregressive moving average (ARMA) models were employed. The Linear and Quantile regression results revealed no SIM effect for BIST All, MSCI France High Dividend Yield (MSCIFRDIV), CDAX, and DivDAX indices. Besides, regression results revealed no SIM effect for BIST Dividend (XTM25) and Indonesia IDX Composite indices. The Quantile regression model for individual stocks in the BIST Dividend (XTM25) index revealed significant positive SIM effects for KORDS, ANSGR, SISE, SAHOL, AKSA, AKGRT, and EREGL. There is no significant positive SIM effect for stocks in the IDX High Dividend (IDXHIDIV20) index. There are significant positive SIM effects for SCHN and SASY of MSCI France High Dividend Yield (MSCIFRDIV) and SIEGN of the DivDAX indices. We recommend for investment managers to closely follow stocks with a positive SIM effect and their forecasted values if they want to take advantage of the market anomaly. The traditional SIM period and dividend payout period coincide with each other. For this reason, the dividend index is a valuable variable that previous researchers did not consider. In our opinion, dividend index and individual stock level SIM inquiry for markets under review is new in the SIM research and leads to new knowledge discovery. Another original point of the article is that it reveals stocks with positive SIM effects and their forecasted values. Forecasting values charts for stocks in each marke t shed light on stock investors about the price movements of the stock in the years ahead.

COVİD-19 PANDEMİSİNİN SEÇİLİ BİST SEKTÖR ENDEKSLERİ ÜZERİNDEKİ ETKİSİ, 2021

Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisi... more Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisini ölçmek amaçlanmıştır. Bu amaçla 05.01.2015-02.07.2021 tarihlerini kapsayan ilgili BİST sektör endekslerinin günlük kapanış fiyatları kullanılmıştır. BİST sektör endekslerinde hem pandeminin etkilerini tespit etmek hem de asimetri ve kaldıraç etkisinin varlığını araştırmak amacıyla Üstel Genelleştirilmiş Otoregresif Koşullu Heterokedastisite (EGARCH) modeli kullanılmıştır. Elde edilen bulgulara göre Covid-19'un, XBLSM, XGIDA, XSGRT sektör getirileri üzerinde pozitif, XTEKS, XTRZM sektör getirileri üzerinde ise negatif bir etkisi olduğu tespit edilmiştir. Pandemi sürecinde XBLSM, XSGRT ve XGIDA getirileri artarken, XTEKS ve XTRZM getirileri azalmıştır. Aynı şekilde oynaklık üzerinde Covid-19'un etkisine bakıldığında XBLSM, XGIDA ve XSGRT sektörlerinin volatilitesi pozitif yönlü etkilenirken, XTEKS, XTRZM, XULAS sektörlerinin volatilitesi negatif yönlü etkilenmiştir.

Volatility Analysis of the Food Sector in Turkey in the Period of COVID-19, 2021

In the literature, there are many studies investigating the direct and indirect effects of the pa... more In the literature, there are many studies investigating the direct and indirect effects of the pandemic. After the first COVID-19 case, these studies began to spread rapidly in Turkey. Due to the measures taken, activities in many sectors were suspended partially and full-time. Among the sectors, the food sector has experienced one of the most challenging processes. The food industry has entered a new era due to reasons such as changing consumption and production behaviors and disruptions in supply chains. The purpose of this study is to determine the impact of the COVID-19 outbreak on the food and beverage industry. In this context, daily data between 03.01.2017-08.04.2021 was used and the Food and Beverage Index (XGIDA) was included in the models as an explanatory variable. In the light of this information, the relationship between the XGIDA index and COVID-19 was examined with Univariate Volatility Models. In addition to the asymmetry and leverage effect in the XGIDA sector, an intra-period forecast was made to determine the fluctuations in the XGIDA sector during the sampling period.

THE VALIDITY OF THE PURCHASING POWER PARITY HYPOTHESIS IN OECD COUNTRIES: EVIDENCE FROM THE FOURIER TEST, 2021

According to purchasing power parity (PPP), the nominal exchange rate between the two currencies ... more According to purchasing power parity (PPP), the nominal exchange rate between the two currencies should be equal to the ratio of the total price levels between the two countries. In other words, it is a simple theory that argues that countries' currencies will have the same purchasing value. In this study, 25 OECD countries is aimed to test the validity of the purchasing power parity hypothesis. The validity of the hypothesis was tested with the monthly data of 1980-Q1 2018-Q12 and Fourier KPSS unit root tests. As a result of the analysis, the validity of the purchasing power parity hypothesis was provided in Brazil,

Eurasian Econometrics, Statistics & Empirical Economics Journal, 2021

Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile geliş... more Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile gelişmiş ve gelişmekte
olan ülkelerin borsaları arasındaki volatilite yayılımı 24.03.2015-21.04.2021 tarihlerine ait günlük veriler
kullanılarak araştırılmıştır. Analizde çok değişkenli GARCH modelleri sınıfında değerlendirilen DCC-GARCH
modeli kullanılmıştır. Elde edilen bulgulara göre BIST100 volatilitesi ile IDX ve MOEX volatilitesi arasında
karşılıklı volatilite etkileşimi bulunamamıştır. BIST100 ile NSE30, CAC40, DAX arasında tek yönlü volatilite
etkileşimi bulunurken BIST100 ile DJIA ve NIFTY50 borsaları arasında ise çift yönlü volatilite etkileşimi
bulunmuştur.

Ekoist: Journal of Econometrics and Statistics, 2021

There are many studies in the literature on child labor. However, most of these studies are based... more There are many studies in the literature on child labor. However, most of these studies are based on statistics on children,
or the factors that cause child labor are explained as economic concepts. The purpose of this study is to investigate the
reasons why school-age children adopt the role of "child laborer" and determine the effects of these factors. In this
context, in order to examine the factors affecting child labor in developing countries, this study has tried to determine
the factors causing child labor with dynamic panel data analysis using MINT Countries data for the period of 1990-2018.
The countries’ development levels and poverty are closely related to child labor. For this reason, the human development
index is added to the model as a dependent variable. Considering the studies in the literature, population growth, primary
school enrollment rate, primary school duration, and labor force participation rate variables were added to the model
as independent variables. At the end of the analysis, all variables were found to be statistically significant. The effect of
population growth and the number of primary school students on the human development index was negative, while the
effect of other variables was positive.

Gazi iktisat ve işletme dergisi, Feb 28, 2024

The direct or indirect impact and importance of educated women on society can be understood accor... more The direct or indirect impact and importance of educated women on society can be understood according to their success in business and the values they bring to the country. It is known that the pre-modern market is subject to a patriarchal system and women in the sector mostly work in areas such as labor and cheap labor. Emotional and intellectual competencies of women are needed to develop a qualified society ahead of the times and for a sustainable life, and it is important for them to be employed. While emphasizing the importance of education, this study investigates the impact of highly educated (university and postgraduate) female workforce on sustainable growth and economy: women on themselves, their environment and their country. Developing or developing countries were selected without a specific country group through World Bank Data and UNDP centers. The values of women's literacy rate, unemployment and highly educated workforce data between 2010 and 2018 were taken. Cluster analysis was performed using the Python language. Countries are divided into 3 groups as a result of applying the K-means method in terms of the GDP impact of the highly educated female workforce. Iran is in the first cluster, where the unemployment rate of the highly educated workforce is lower than the average, Egypt and Bangladesh are in the second cluster, where employment is gradually decreasing, and Turkey, Brazil, Indonesia, South Africa and Mexico are in the third cluster, where the literacy rate and labor force averages are above a certain level and close to each other has received. The sustainable growth impact of the advanced educated female workforce is discussed in the conclusion.

DergiPark (Istanbul University), Apr 10, 2023

Ekonomi bilimleri dergisi, Jan 13, 2024

Journal of business, economics and finance, Dec 30, 2023

Yönetim ve ekonomi araştırmaları dergisi, Nov 26, 2023

DergiPark (Istanbul University), Apr 20, 2023

The increase in the human capital of countriesensures their growthand development by increasing t... more The increase in the human capital of countriesensures their growthand development by increasing the capital investmentrates by ensuring the effective and efficientuse of production factors. The fact that women, who make up half of the society, are not included in economic activities is an important disruption that affects social welfare by disrupting the grow than development of countries. In thisstudy, which aims to test there lationship between the female labor force participation rate and economic growth, Turkey, which has experienced a growth that does not create employment, is taken into consideration, and the female labor force participation rate (15 yearsandover, annual) data obtained from the UNDP for the period 1990-2021, and the World Bank's data. GDP growth (% perannum) data from according to the findings, it has been determined that the labor force participation rate of women is statistically significantand has a positive effect on economic growth. A %1 increase in women's labor force participation rate causes a %0.12 increase in growth. According to the findings obtained from the Granger Causality Test, which was applied to question the causality relationship between the variables, it reveals that there is one-waycausality from GDP to womens employment. This study is important in terms of expanding the typology as well as emphasizing the negative impact of gender-based preferences and barriers on economic growth and social welfare.

Eurasian Econometrics Statistics & Emprical Economics Journal

Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile geliş... more Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile gelişmiş ve gelişmekte olan ülkelerin borsaları arasındaki volatilite yayılımı 24.03.2015-21.04.2021 tarihlerine ait günlük veriler kullanılarak araştırılmıştır. Analizde çok değişkenli GARCH modelleri sınıfında değerlendirilen DCC-GARCH modeli kullanılmıştır. Elde edilen bulgulara göre BIST100 volatilitesi ile IDX ve MOEX volatilitesi arasında karşılıklı volatilite etkileşimi bulunamamıştır. BIST100 ile NSE30, CAC40, DAX arasında tek yönlü volatilite etkileşimi bulunurken BIST100 ile DJIA ve NIFTY50 borsaları arasında ise çift yönlü volatilite etkileşimi bulunmuştur.

DergiPark (Istanbul University), Sep 23, 2021

Bu çalışmada, popülerliği son yıllarda artan kripto paralar sınıfında değerlendirilen Bitcoin ile... more Bu çalışmada, popülerliği son yıllarda artan kripto paralar sınıfında değerlendirilen Bitcoin ile Euro getirileri arasındaki volatilite etkileşimini incelemek için 02.02.2014-28.02.2021 dönemine ait günlük veriler kullanılmıştır. Değişkenlere ait getirilerin zaman içindeki hareketini incelemek için oluşturulan grafiklerden volatilite kümelenmesi tespit edilmiş ve analiz için "Çok Değişkenli GARCH Modelleri" kullanılmıştır. Modellerden elde edilen sonuçlar karşılaştırılmış ve log-olabilirlik değeri mutlak değerce en büyük bulunan "BEKK-GARCH Modeli" uygun model kabul edilmiştir. Bulgular incelendiğinde, Euro ile Bitcoin arasında çift yönlü volatilite etkileşimi bulunmuştur. Ayrıca DCC-GARCH modeli sonuçlarına göre ise iki getiri arasında asimetri ilişkisi ve pozitif, güçlü bir dinamik korelasyon tespit edilmiştir

DergiPark (Istanbul University), Mar 9, 2022

In order to understand relationships between different currencies, Econometrics presents us a lot... more In order to understand relationships between different currencies, Econometrics presents us a lot of tools. One of these tools ARCH Models are often used by many papers. On the other side, anomalies, and volatilities are the main psychological results of financial markets. This paper, it is aimed to determine some anomalies of currencies with an ARCH model as EGARCH (p, q) model with data 03.02.2014-31.12.2020 period on Bitcoin and Euro Currency. It is made in this paper clear that financial investors behave towards financial assets within anomalies and volatilities. Therefore, it is proved that the main focal point of financial epistemology should be anomalies, so volatilities also in financial innovations.

Computers, Materials & Continua

Construction Industry operates relying on various key economic indicators. One of these indicator... more Construction Industry operates relying on various key economic indicators. One of these indicators is material prices. On the other hand, cost is a key concern in all operations of the construction industry. In the uncertain conditions, reliable cost forecasts become an important source of information. Material cost is one of the key components of the overall cost of construction. In addition, cost overrun is a common problem in the construction industry, where nine out of ten construction projects face cost overrun. In order to carry out a successful cost management strategy and prevent cost overruns, it is very important to find reliable methods for the estimation of construction material prices. Material prices have a time dependent nature. In order to increase the foreseeability of the costs of construction materials, this study focuses on estimation of construction material indices through time series analysis. Two different types of analysis are implemented for estimation of the future values of construction material indices. The first method implemented was Autoregressive Integrated Moving Average (ARIMA), which is known to be successful in estimation of time series having a linear nature. The second method implemented was Non-Linear Autoregressive Neural Network (NARNET) which is known to be successful in modeling and estimating of series with non-linear components. The results have shown that depending on the nature of the series, both these methods can successfully and accurately estimate the future values of the indices. In addition, we found out that Optimal NARNET architectures which provide better accuracy in estimation of the series can be identified/discovered as result of grid search on NARNET hyperparameters.

Construction Industry operates relying on various key economic indicators. One of these indicator... more Construction Industry operates relying on various key economic indicators. One of these indicators is material prices. On the other hand, cost is a key concern in all operations of the construction industry. In the uncertain conditions, reliable cost forecasts become an important source of information. Material cost is one of the key components of the overall cost of construction. In addition, cost overrun is a common problem in the construction industry, where nine out of ten construction projects face cost overrun. In order to carry out a successful cost management strategy and prevent cost overruns, it is very important to find reliable methods for the estimation of construction material prices. Material prices have a time dependent nature. In order to increase the foreseeability of the costs of construction materials, this study focuses on estimation of construction material indices through time series analysis. Two different types of analysis are implemented for estimation of the future values of construction material indices. The first method implemented was Autoregressive Integrated Moving Average (ARIMA), which is known to be successful in estimation of time series having a linear nature. The second method implemented was Non-Linear Autoregressive Neural Network (NARNET) which is known to be successful in modeling and estimating of series with non-linear components. The results have shown that depending on the nature of the series, both these methods can successfully and accurately estimate the future values of the indices. In addition, we found out that Optimal NARNET architectures which provide better accuracy in estimation of the series can be identified/discovered as result of grid search on NARNET hyperparameters.

Stratejik ve Sosyal Araştırmalar Dergisi

It is a well-known fact that economic freedom is one of the important stimulators of its impact o... more It is a well-known fact that economic freedom is one of the important stimulators of its impact on the level of development and welfare of a country. In this study, data from the Fragile Five Countries covering the years 1999-2018 were used to investigate the effect of the economic freedom index, which is used to determine and measure economic freedoms, on the human development index, which is used to measure human welfare. According to the results obtained, a 1% increase in the economic freedom index increases the human development index by 0.54% for India, 0.30% for Brazil, 0.61% for Turkey. For Indonesia, it decreases by 0.48%. In South Africa, however, no effect of the economic freedom index on the human development index was detected. When comments are made for all countries, the 1% increase in the economic freedom index increases the human development index by 1.84%.

Yönetim ve Ekonomi Araştırmaları Dergisi, 2021

Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisi... more Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisini ölçmek amaçlanmıştır. Bu amaçla 05.01.2015-02.07.2021 tarihlerini kapsayan ilgili BİST sektör endekslerinin günlük kapanış fiyatları kullanılmıştır. BİST sektör endekslerinde hem pandeminin etkilerini tespit etmek hem de asimetri ve kaldıraç etkisinin varlığını araştırmak amacıyla Üstel Genelleştirilmiş Otoregresif Koşullu Heterokedastisite (EGARCH) modeli kullanılmıştır. Elde edilen bulgulara göre Covid-19'un, XBLSM, XGIDA, XSGRT sektör getirileri üzerinde pozitif, XTEKS, XTRZM sektör getirileri üzerinde ise negatif bir etkisi olduğu tespit edilmiştir. Pandemi sürecinde XBLSM, XSGRT ve XGIDA getirileri artarken, XTEKS ve XTRZM getirileri azalmıştır. Aynı şekilde oynaklık üzerinde Covid-19'un etkisine bakıldığında XBLSM, XGIDA ve XSGRT sektörlerinin volatilitesi pozitif yönlü etkilenirken, XTEKS, XTRZM, XULAS sektörlerinin volatilitesi negatif yönlü etkilenmiştir.

Ekoist: Journal of Econometrics and Statistics, 2021

There are many studies in the literature on child labor. However, most of these studies are based... more There are many studies in the literature on child labor. However, most of these studies are based on statistics on children, or the factors that cause child labor are explained as economic concepts. The purpose of this study is to investigate the reasons why school-age children adopt the role of "child laborer" and determine the effects of these factors. In this context, in order to examine the factors affecting child labor in developing countries, this study has tried to determine the factors causing child labor with dynamic panel data analysis using MINT Countries data for the period of 1990-2018. The countries' development levels and poverty are closely related to child labor. For this reason, the human development index is added to the model as a dependent variable. Considering the studies in the literature, population growth, primary school enrollment rate, primary school duration, and labor force participation rate variables were added to the model as independent variables. At the end of the analysis, all variables were found to be statistically significant. The effect of population growth and the number of primary school students on the human development index was negative, while the effect of other variables was positive.

The “Sell in May” Effect: An Empirical Analysis from Turkey, Indonesia, France, and Germany , 2022

This study aims to provide empirical insight into the "Sell in May" (SIM) effect in Turkey, Indon... more This study aims to provide empirical insight into the "Sell in May" (SIM) effect in Turkey, Indonesia, France, and Germany stock exchange markets. We examined Turkey BIST All, BIST Dividend (XTM25), Indonesia IDX Composite, France CAC All (PAX), MSCI France High Dividend Yield (MSCIFRDIV), and Germany CDAX, DivDAX price indices, and individual stocks in dividend indices. Average monthly return data for January 2015 and December 2020 were used for the research. Linear, Quantile regression, and Autoregressive moving average (ARMA) models were employed. The Linear and Quantile regression results revealed no SIM effect for BIST All, MSCI France High Dividend Yield (MSCIFRDIV), CDAX, and DivDAX indices. Besides, regression results revealed no SIM effect for BIST Dividend (XTM25) and Indonesia IDX Composite indices. The Quantile regression model for individual stocks in the BIST Dividend (XTM25) index revealed significant positive SIM effects for KORDS, ANSGR, SISE, SAHOL, AKSA, AKGRT, and EREGL. There is no significant positive SIM effect for stocks in the IDX High Dividend (IDXHIDIV20) index. There are significant positive SIM effects for SCHN and SASY of MSCI France High Dividend Yield (MSCIFRDIV) and SIEGN of the DivDAX indices. We recommend for investment managers to closely follow stocks with a positive SIM effect and their forecasted values if they want to take advantage of the market anomaly. The traditional SIM period and dividend payout period coincide with each other. For this reason, the dividend index is a valuable variable that previous researchers did not consider. In our opinion, dividend index and individual stock level SIM inquiry for markets under review is new in the SIM research and leads to new knowledge discovery. Another original point of the article is that it reveals stocks with positive SIM effects and their forecasted values. Forecasting values charts for stocks in each marke t shed light on stock investors about the price movements of the stock in the years ahead.

COVİD-19 PANDEMİSİNİN SEÇİLİ BİST SEKTÖR ENDEKSLERİ ÜZERİNDEKİ ETKİSİ, 2021

Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisi... more Tekstil-Deri, Turizm, Ulaştırma olmak üzere toplam 8 sektör endeksinde Covid-19 salgınının etkisini ölçmek amaçlanmıştır. Bu amaçla 05.01.2015-02.07.2021 tarihlerini kapsayan ilgili BİST sektör endekslerinin günlük kapanış fiyatları kullanılmıştır. BİST sektör endekslerinde hem pandeminin etkilerini tespit etmek hem de asimetri ve kaldıraç etkisinin varlığını araştırmak amacıyla Üstel Genelleştirilmiş Otoregresif Koşullu Heterokedastisite (EGARCH) modeli kullanılmıştır. Elde edilen bulgulara göre Covid-19'un, XBLSM, XGIDA, XSGRT sektör getirileri üzerinde pozitif, XTEKS, XTRZM sektör getirileri üzerinde ise negatif bir etkisi olduğu tespit edilmiştir. Pandemi sürecinde XBLSM, XSGRT ve XGIDA getirileri artarken, XTEKS ve XTRZM getirileri azalmıştır. Aynı şekilde oynaklık üzerinde Covid-19'un etkisine bakıldığında XBLSM, XGIDA ve XSGRT sektörlerinin volatilitesi pozitif yönlü etkilenirken, XTEKS, XTRZM, XULAS sektörlerinin volatilitesi negatif yönlü etkilenmiştir.

Volatility Analysis of the Food Sector in Turkey in the Period of COVID-19, 2021

In the literature, there are many studies investigating the direct and indirect effects of the pa... more In the literature, there are many studies investigating the direct and indirect effects of the pandemic. After the first COVID-19 case, these studies began to spread rapidly in Turkey. Due to the measures taken, activities in many sectors were suspended partially and full-time. Among the sectors, the food sector has experienced one of the most challenging processes. The food industry has entered a new era due to reasons such as changing consumption and production behaviors and disruptions in supply chains. The purpose of this study is to determine the impact of the COVID-19 outbreak on the food and beverage industry. In this context, daily data between 03.01.2017-08.04.2021 was used and the Food and Beverage Index (XGIDA) was included in the models as an explanatory variable. In the light of this information, the relationship between the XGIDA index and COVID-19 was examined with Univariate Volatility Models. In addition to the asymmetry and leverage effect in the XGIDA sector, an intra-period forecast was made to determine the fluctuations in the XGIDA sector during the sampling period.

THE VALIDITY OF THE PURCHASING POWER PARITY HYPOTHESIS IN OECD COUNTRIES: EVIDENCE FROM THE FOURIER TEST, 2021

According to purchasing power parity (PPP), the nominal exchange rate between the two currencies ... more According to purchasing power parity (PPP), the nominal exchange rate between the two currencies should be equal to the ratio of the total price levels between the two countries. In other words, it is a simple theory that argues that countries' currencies will have the same purchasing value. In this study, 25 OECD countries is aimed to test the validity of the purchasing power parity hypothesis. The validity of the hypothesis was tested with the monthly data of 1980-Q1 2018-Q12 and Fourier KPSS unit root tests. As a result of the analysis, the validity of the purchasing power parity hypothesis was provided in Brazil,

Eurasian Econometrics, Statistics & Empirical Economics Journal, 2021

Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile geliş... more Uluslararası borsaların birbirini etkileme gücünü tespit etmek amacıyla Türkiye Borsası ile gelişmiş ve gelişmekte
olan ülkelerin borsaları arasındaki volatilite yayılımı 24.03.2015-21.04.2021 tarihlerine ait günlük veriler
kullanılarak araştırılmıştır. Analizde çok değişkenli GARCH modelleri sınıfında değerlendirilen DCC-GARCH
modeli kullanılmıştır. Elde edilen bulgulara göre BIST100 volatilitesi ile IDX ve MOEX volatilitesi arasında
karşılıklı volatilite etkileşimi bulunamamıştır. BIST100 ile NSE30, CAC40, DAX arasında tek yönlü volatilite
etkileşimi bulunurken BIST100 ile DJIA ve NIFTY50 borsaları arasında ise çift yönlü volatilite etkileşimi
bulunmuştur.

Ekoist: Journal of Econometrics and Statistics, 2021

There are many studies in the literature on child labor. However, most of these studies are based... more There are many studies in the literature on child labor. However, most of these studies are based on statistics on children,
or the factors that cause child labor are explained as economic concepts. The purpose of this study is to investigate the
reasons why school-age children adopt the role of "child laborer" and determine the effects of these factors. In this
context, in order to examine the factors affecting child labor in developing countries, this study has tried to determine
the factors causing child labor with dynamic panel data analysis using MINT Countries data for the period of 1990-2018.
The countries’ development levels and poverty are closely related to child labor. For this reason, the human development
index is added to the model as a dependent variable. Considering the studies in the literature, population growth, primary
school enrollment rate, primary school duration, and labor force participation rate variables were added to the model
as independent variables. At the end of the analysis, all variables were found to be statistically significant. The effect of
population growth and the number of primary school students on the human development index was negative, while the
effect of other variables was positive.

Kırılgan Besli Ulkelerde Ekonomik Ozgurlugun Insani Gelismislik Uzerindeki Etkisi, 2022

Bilgi ve İletişim Teknolojilerinin Büyümeye Etkisi: Panel Veri Uygulaması, 2018

In this study, between 2000 and 2015, the relationship between economic growth and information an... more In this study, between 2000 and 2015, the relationship between economic growth and information and communication technologies for developed and developing countries was analyzed with the aid of panel data models. Panel data models were estimated by taking G-8 countries for developed countries and MİNT countries for developing countries. Information communication technologies and economic growth have often been examined in the literature by using the Generalized Moments Method and panel cointegration method. Here, the relationship between the export of information communication technologies and economic growth will be dealt with by panel data analysis and the main aim will be to model the behavior of economic and technological indicators used in the study in panel data models. In the first part, the theoretical structure of the relationship between information and communication technologies and economic growth will be discussed and a study on the subject will be given.In the second part, information about the econometric concept of the methods used in working will be given.In the third part, the results of the statistical analyzes between the econometric analyzes and the variables will be given in a table. The study was terminated by interpreting the results reached for the countries.

An Empirical Analysis for Food Sector and COVID-19 Relationship in Turkey, 2021

The first detectable point of the COVID-19 pandemic that emerged in November 2019 was the Huanan ... more The first detectable point of the COVID-19 pandemic that emerged in November 2019 was the Huanan seafood market in Wuhan, China. Due to COVID-19, an international emergency was declared by the World Health Organization on January 30, 2020. By March 11, 2020, it was announced that the coronavirus was an epidemic that affected many geographies and therefore a new pandemic had begun in the world. Dr Tedros Adhanom Ghebreyesus, Director General of the World Health Organization (WHO), stated in a news briefing on March 11, 2020 that the number of cases outside China has increased 13 times in the last 2 weeks, and the number of countries with cases has tripled, and more is expected. In the statement made by the World Health Organization, the alarming level and severity of the spread in the epidemic explained. However, they also stated that there is concern about the inaction, they insisted that countries take immediate action to contain the virus. First COVID-19 case detected at March 11 in Turkey and it was announced by the Ministry of Health. The first death due to the virus in the country occurred on March 15, 2020. Health Minister Fahrettin Koca, announced that virus spread all over Turkey in the beginning of April 2020. Then the pandemic started to test countries in every aspect. Since the pandemic started, many studies continue to investigate the direct and indirect effects of the pandemic. After the first case of COVID-19, it also began to spread rapidly in Turkey. Due to the measures taken, activities in many sectors were stopped partially and full time. Among the industries, the food industry experienced one of the most challenging process. The food industry has entered a new era due to reasons such as changing consumption and production behaviour and disruptions in supply chains. Interactions between food sector and the pandemic started to analyse in the world and Turkey. In this context, the purpose of this study is to determine the impact of the COVID-19 outbreak on the yield and volatility of the food and beverage industry. For this purpose, daily data between 03.01.2017-08.04.2021 were used and the Food and Beverage Index (XGIDA) was included in the models as a variable. In the light of this information, the extent to which the XGIDA index is affected by COVID-19 was examined with Univariate Volatility Models. In order to determine the asymmetry and leverage effect in the XGIDA sector, as well as to determine the fluctuations in the XGIDA sector during the sampling period, a foresight was made within the period.

E-7 ÜLKELERİNDE CARİ AÇIĞIN SÜRDÜRÜLEBİLİRLİĞİ: FOURİER ANALİZLERİ, 2021

Cari açık, finansal istikrarın korunabilmesi için açık vermemesi gereken önemli bir makroekonomik... more Cari açık, finansal istikrarın korunabilmesi için açık vermemesi gereken önemli bir makroekonomik gösterge olup dikkatle izlenmesi gereken bir risk unsuru olarak algılanmaktadır. Ülkeler açısından doğru politika belirleyebilmek için, sürdürülebilirliğin açıklanması büyük öneme sahiptir. Bu çalışmada da E-7 ülkeleri olarak anılan Türkiye, Meksika, Endonezya, Hindistan, Brezilya, Çin ve Rusya 'da cari açıklığın sürdürülebilirliği araştırılmak amacıyla 1980-2019 dönemine ait yıllık veriler kullanılmıştır. Cari işlemler açığının sürdürülebilir olup olmamasını araştırmak amacıyla Cari işlemler hesabı dengesinin (CAD) gayrisafi yurtiçi hasılaya (GSYH) oranını gösteren seri açıklayıcı değişken olarak modele dahil edilmiştir. Rusya veri eksikliği nedeniyle analize dahil edilmemiştir. Türkiye, Meksika, Endonezya, Hindistan, Brezilya ve Çin'de cari açıklığın sürdürülebilirliği Fourier KPSS ve Fouirer ADF birim kök testleri ile incelenmiştir. Fourier KPSS testi sonuçlarına göre Brezilya hariç diğer ülkelerde cari açığın sürdürülemediği sonucuna ulaşılmıştır. Fourier ADF sonuçlarına göre ise Çin, Hindistan ve Brezilya için cari açığın sürdürülemediği ancak Endonezya, Meksika ve Türkiye için cari açığın sürdürülebilir olduğu tespit edilmiştir.

Proceedings of the 3rd Advanced Enginering Days , 2022

Construction Material Price ARIMA Time Series Construction materials has a key impact on the cost... more Construction Material Price ARIMA Time Series Construction materials has a key impact on the cost of construction. In construction industry it is important to foresee the trends of material prices to prevent, cost overruns during the construction stage and bankruptcy of the contractors. The material price trends have a time dependent nature, and time series analysis methods can be utilized to model and estimate them. This study focuses on modeling and forecasting the trends in material prices through Box-Jenkins methodology. In this context, an economic indicator named General Trend in Construction Materials Industry is modelled with an ARIMA (1,1,0) model. The forecasts done with the model indicate that the model can successfully predict the future values of the indicator.

Proceedings of the 3rd Advanced Enginering Days, 2022

Construction Material Time Series ANN NARNET The price of materials is dependent on different fac... more Construction Material Time Series ANN NARNET The price of materials is dependent on different factors such as raw material costs, production costs, and cost of logistics. The construction industry professionals face difficulties in times when there are fluctuations in material prices. This study aimed to model the expectancy of trends in material prices through a time series analysis, as the expectancy of trend is a time dependent dataset.. In this context, the study is focused on utilization of a special type of ANN (and special type of RNN) architecture known as Nonlinear Autoregressive Neural Network (NARNET). Ten different NARNET configurations were implemented in MATLAB and their performance were tested in the study. The results have shown that NARNETs are able to model the expectancy of trend accurately.

TÜRKİYE’DE İŞSİZLİK HİSTERİSİNİN DOĞRUSAL OLMAYAN BİRİM KÖK TESTLERİYLE SINANMASI, 2022

Gelişmiş ve gelişmekte olan ekonomilerde işsizlik kavramı, ekonomik, sosyal ve kültürel açıdan bü... more Gelişmiş ve gelişmekte olan ekonomilerde işsizlik kavramı, ekonomik,
sosyal ve kültürel açıdan büyük öneme sahiptir. İşsizliğin nedenlerinin belirlenmesinin yanısıra sonuçlarının da belirlenmesi gerekmektedir. Dolayısıyla
ülkelerde işsizlik histerisinin varlığının tespit edilmesi ve politikaların bu yönde geliştirilmesi oldukça önemlidir.
Bu çalışmada da Türkiye’de hem toplam işsizlik oranı hem de ayrı ayrı
kadın ve erkek işsizlik oranlarındaki histeri etkisini araştırmak hedeflenmiştir.
Bu amaçla kadın işsizlik oranı erkek işsizlik oranı ve toplam işsizlik oranı değişkenlerinin 1991-2019 dönemine ait yıllık verileri kullanılmıştır.
Kadın, erkek ve toplam işsizlik oranları serilerinin tanımlayıcı istatistiklerine göre ortalama kadın işsizlik oranının %9.91 ile en yüksek olduğu, ortalama erkek işsizlik oranının %9.01 ile ortalama işsizlik oranının altında seyrettiği görülmektedir. En yüksek işsizlik oranı %16.38 ile kadın işsizliğinde tespit
edilmiştir. Ayıca işsizlik oranı standart sapması en yüksek olan değer kadın
işsizlik oranına aittir.2001 ve 2008 krizlerinin yaşandığı dönemlerde işsizlik oranlarındaki ani
artışlar elde edilen grafiklere yansımıştır. Bu amaçla, işsizlik oranlarında histeri etkisi incelenirken yapısal değişimleri dikkate alan Leybourne, Newbold
ve Vougas (1998), Hepsağ (2021) ile Harvey ve Mills (2002) birim kök testleri
kullanılmıştır.
Öncelikle kadın, erkek ve toplam işsizlik oranlarının doğrusallık durumu
Harvey ve Leybourne (2007) ve Harvey, Leybourne ve Xiao (2008) testleriyle
araştırılmıştır. Seriler için doğrusal dışılığın geçerli olduğu tespit edilmiştir.
Hem sabitte hem trendde yumuşak kırılmayı dikkate alan Leybourne, Newbold ve Vougas (Model C) test istatistiği ile kritik değer karşılaştırıldığında kadın işsizlik oranı serisinin durağan, erkek ve toplam işsizlik oranı serisinin ise
birim köklü olduğu tespit edilmiştir. Yani kadın işsizlik oranı değişkenine etki
eden bir şok zamanla azalarak kaybolmaktadır. Dolayısıyla erkek ve toplam
işsizlik oranı değişkeninde işsizlik histerisinin varlığı tespit edilmiştir. İki yumuşak kırılmaya izin veren Harvey ve Mills (2002) testi ile hem sabitte hem
trendde bir yumuşak kırılmayı dikkate alan Hepsağ(2021) testi sonuçlarına
göre kadın, erkek ve toplam işsizlik oranında oluşacak şoklar zamanla etkisini kaybetmeyecektir. Dolayısıyla Türkiye’de kadın, erkek ve toplam işsizlik
oranında histeri etkisi tespit edilmiş, doğal oran hipotezinin geçerli olmadığı
sonucuna ulaşılmıştır.

OECD ÜLKELERİNDE EĞİTİM HARCAMALARI VE TEKNOLOJİ ETKİLEŞİMİ: PANEL NEDENSELLİK VE PANEL VEKTÖR OTOREGRESİF MODELLER, 2022

Computers,Materials & Continua, 2023

Construction Industry operates relying on various key economic indicators. One of these indicator... more Construction Industry operates relying on various key economic indicators. One of these indicators is material prices. On the other hand, cost is a key concern in all operations of the construction industry. In the uncertain conditions, reliable cost forecasts become an important source of information. Material cost is one of the key components of the overall cost of construction. In addition, cost overrun is a common problem in the construction industry, where nine out of ten construction projects face cost overrun. In order to carry out a successful cost management strategy and prevent cost overruns, it is very important to find reliable methods for the estimation of construction material prices. Material prices have a time dependent nature. In order to increase the foreseeability of the costs of construction materials, this study focuses on estimation of construction material indices through time series analysis. Two different types of analysis are implemented for estimation of the future values of construction material indices. The first method implemented was Autoregressive Integrated Moving Average (ARIMA), which is known to be successful in estimation of time series having a linear nature. The second method implemented was Non-Linear Autoregressive Neural Network (NARNET) which is known to be successful in modeling and estimating of series with non-linear components. The results have shown that depending on the nature of the series, both these methods can successfully and accurately estimate the future values of the indices. In addition, we found out that Optimal NARNET architectures which provide better accuracy in estimation of the series can be identified/discovered as result of grid search on NARNET hyperparameters.