Omay, Tolga

Profile Picture
Profile URL
https://hdl.handle.net/20.500.14411/7237
Name Variants
T.,Omay
Omay, Tolga
O., Tolga
Tolga, Omay
Omay,T.
O.,Tolga
T., Omay
Omay T.
Job Title
Profesor Doktor
Email Address
tolga.omay@atilim.edu.tr
Main Affiliation
Economics
Status
Website
ORCID ID
Scopus Author ID
23978235900
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
GDI-4259-2022

Sustainable Development Goals

NO POVERTY1
NO POVERTY
0
Research Products
ZERO HUNGER2
ZERO HUNGER
0
Research Products
GOOD HEALTH AND WELL-BEING3
GOOD HEALTH AND WELL-BEING
2
Research Products
QUALITY EDUCATION4
QUALITY EDUCATION
0
Research Products
GENDER EQUALITY5
GENDER EQUALITY
0
Research Products
CLEAN WATER AND SANITATION6
CLEAN WATER AND SANITATION
0
Research Products
AFFORDABLE AND CLEAN ENERGY7
AFFORDABLE AND CLEAN ENERGY
3
Research Products
DECENT WORK AND ECONOMIC GROWTH8
DECENT WORK AND ECONOMIC GROWTH
11
Research Products
INDUSTRY, INNOVATION AND INFRASTRUCTURE9
INDUSTRY, INNOVATION AND INFRASTRUCTURE
3
Research Products
REDUCED INEQUALITIES10
REDUCED INEQUALITIES
2
Research Products
SUSTAINABLE CITIES AND COMMUNITIES11
SUSTAINABLE CITIES AND COMMUNITIES
1
Research Products
RESPONSIBLE CONSUMPTION AND PRODUCTION12
RESPONSIBLE CONSUMPTION AND PRODUCTION
1
Research Products
CLIMATE ACTION13
CLIMATE ACTION
7
Research Products
LIFE BELOW WATER14
LIFE BELOW WATER
2
Research Products
LIFE ON LAND15
LIFE ON LAND
1
Research Products
PEACE, JUSTICE AND STRONG INSTITUTIONS16
PEACE, JUSTICE AND STRONG INSTITUTIONS
0
Research Products
PARTNERSHIPS FOR THE GOALS17
PARTNERSHIPS FOR THE GOALS
7
Research Products
Documents

80

Citations

1218

h-index

20

Go to Scopus profile
Documents

74

Citations

1075

Go to WoS profile
Scholarly Output

70

Articles

58

Views / Downloads

269/2443

Supervised MSc Theses

4

Supervised PhD Theses

4

WoS Citation Count

435

Scopus Citation Count

503

Patents

0

Projects

0

WoS Citations per Publication

6.21

Scopus Citations per Publication

7.19

Open Access Source

34

Supervised Theses

8

JournalCount
Computational Economics6
Applied Economics5
Mathematics3
Springer Proceedings in Business and Economics -- 4th International Conference on Banking and Fice Perspectives, ICBFP 2019 -- 2 May 2019 through 3 May 2019 -- Famagusta -- 2737293
Environmental Modeling & Assessment2
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Scholarly Output Search Results

Now showing 1 - 10 of 70
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    Master Thesis
    Küresel Likidite Koşullarının Borsa İstanbul Endekslerine Etkileri
    (2020) Altuntaş, Canan Özlem; Omay, Tolga
    Küreselleşme ve finansal serbestleşmenin bir sonucu olarak, bir ülkenin finansal piyasasında yaşanan bir değişiklik yerel bir etkiyle sınırlı kalmamakta, diğer finansal piyasalara da yayılmaktadır. Bu tez çalışmasında, küresel likidite koşullarının Borsa İstanbul üzerindeki etkilerinin analiz edilmesi amaçlanmıştır. Bu kapsamda, 01.01.2010 – 31.03.2020 tarihleri arası BIST 100 endeksi log-getirileri ile VIX endeksinin günlük kapanış verileri, bir Çok Değişkenli GARCH model spesifikasyonu olan Sabit Koşullu Korelasyon GARCH (CCC-GARCH) yöntemi ve Gecikmesi Dağıtılmış Otoregresif (ARDL) model kullanılarak analiz edilmiştir. Çalışmada VIX endeksi, global likiditeyi temsilen vekil değişken olarak kullanılmıştır. Elde edilen ampirik sonuçlar, beklentilerle paralel olarak VIX ve BIST 100 endeksleri arasında negatif korelasyon olduğu, BIST 100 endeksinin küresel finansal piyasalarla tam entegre olduğu ve dolayısıyla küresel likidite koşullarında meydana gelen bir şokun BIST 100 endeksini de etkilediği yönündedir.
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    Article
    Citation - WoS: 10
    Citation - Scopus: 11
    Is There Convergence in Renewable Energy Deployment? Evidence From a New Panel Unit Root Test With Smooth and Sharp Structural Breaks
    (Pergamon-elsevier Science Ltd, 2023) Corakci, Aysegul; Omay, Tolga
    This study examines whether the contribution of renewable energy to the total primary energy supply converges in a panel of 24 OECD countries over the period 1960-2020. To this end, a new panel unit root test that allows for both sharp and smooth breaks is proposed to test for the stochastic convergence hypothesis. Although renewable energy convergence is not rejected when the newly proposed test is applied to the full panel of OECD countries, it found only moderate support within the members of the panel using a sequential panel selection methodology. In fact, in two high-income OECD countries, the contribution of renewable energy to the primary energy supply shows no sign of convergence: Poland and Iceland. Therefore, the renewable energy shares seem to be converging to a common steady state in only a group of OECD countries over the long run. This uneven pattern of convergence, in turn, suggests that the OECD countries are still far away from developing a common sustainable renewable energy target, calling for urgent international policy cooperation to encourage the divergent econo-mies to seek out the menu of policies that ensure the worldwide success of renewable energy transformation.
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    Article
    Citation - WoS: 9
    Citation - Scopus: 11
    Current Account and Credit Growth: the Role of Household Credit and Financial Depth
    (Elsevier Science inc, 2020) Ekinci, Mehmet Fatih; Ekinci, Mehmet Fatih; Omay, Tolga; Omay, Tolga; Ekinci, Mehmet Fatih; Omay, Tolga; Economics; Economics
    Understanding the impact of financial variables on the current account balance is one of the priorities of academic literature and policymakers. Evidence from a broad panel of advanced and emerging countries shows that an increase in credit growth is associated with a significant deterioration in the current account balance. When we examine the roles of the components of credit, we find that an increase in household credit causes a significant decline in the current account balance, whereas an increase in business loans has no significant effect. Therefore, our findings indicate that the significant negative impact of credit growth on the current account balance is driven by household credit. Furthermore, we show that total and household credit growth rates have a stronger negative effect on the current account balance for lower levels of financial depth. Our results suggest that targeted policy measures that curb household credit growth might be more effective to reduce external imbalances particularly at the early stages of financial deepening.
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    Doctoral Thesis
    Uygulanan Politikaların Süt Üretimine Etkisi: Seçilmiş Ab Ülkeleri ve Türkiye Karşılaştırması
    (2024) Güncer, Kemal; Omay, Tolga
    Dünya nüfusundaki artışın, gelir artışları ile tarım ürünlerine olan talebi artırması ve tarımsal ürün talebinin bileşiminde değişikliklere yol açması beklenmektedir. Bu büyüyen gıda talebini karşılamak için tarımsal üretimde önemli artışlar gereklidir. Ancak, dünya üzerinde tarımsal üretimde kullanılabilecek arazi miktarının sınırlıdır. Bu durum, tarımda üretim artışları için birim arazide elde edilen üretim miktarının artırılması yani verimlilik artışlarının zorunlu olduğunu göstermektedir. Ayrıca tarım sektöründe devlet müdahalesi yaygın olarak uygulanmakta ve üretimdeki artışlar makroekonomik politika ve düzenlemelere bağlı kalmaktadır. Tarımsal destek politikalarının verimlilik üzerindeki etkisi desteklerin niteliğine bağlıdır. Verimlilik ölçütleri arasında kısmi faktör verimliliği (KFV) ve toplam faktör verimliliği (TFV) bulunmakta, ancak TFV literatürde daha baskın olarak kullanılmaktadır. Tarım sektöründe çalışan verilerin kalitesi dikkate alındığında geleneksel TFV yaklaşımlarının büyümenin nedenleri hakkında yeterli bilgi sağlamamakta ve büyümenin teknolojik ve kurumsal değişim, tarımsal politika ve tasarım ile ilişkilisini ele almaktadır. Bu nedenle, çalışmada, KFV ve TFV yaklaşımlarının eksikliklerini gidermek ve tarımsal büyüme üzerindeki etkileri analiz etmek amacıyla yeni bir ölçüt olarak birleştirilmiş yaklaşım geliştirilmiştir. Bu çerçevede, Türkiye'deki süt üretiminin belirleyicilerini analiz etmek ve çözümlemek amacıyla 1961-2017 dönemi üzerine odaklanılmış, aynı dönemde, hayvancılık ve süt sektörlerini yoğun şekilde destekleyen Almanya, Fransa ve Hollanda gibi üç Avrupa Birliği ülkesi ile regresyon analizini de içeren karşılaştırmalı bir çalışma yapılmıştır.
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    Article
    Citation - WoS: 6
    Citation - Scopus: 4
    Is real per capita state personal income stationary? New nonlinear, asymmetric panel-data evidence
    (Wiley, 2020) Emirmahmutoglu, Furkan; Gupta, Rangan; Miller, Stephen M.; Omay, Tolga
    This paper re-examines the stochastic properties of U.S. state real per capita personal income, using new panel unit-root procedures. The new developments incorporate non-linearity, asymmetry, and cross-sectional correlation within panel-data estimation. Including nonlinearity and asymmetry finds that 43 states exhibit stationary real per capita personal income whereas including only nonlinearity produces 42 states that exhibit stationarity. Stated differently, we find that two states exhibit nonstationary real per capita personal income when considering nonlinearity, asymmetry, and cross-sectional dependence.
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    Article
    Citation - WoS: 11
    Testing the Hysteresis Effect in the Us State-Level Unemployment Series
    (Routledge Journals, Taylor & Francis Ltd, 2020) Omay, Tolga; Ozcan, Burcu; Shahbaz, Muhammed
    This paper re-examines the stochastic time series behaviour of the monthly unemployment rate in 50 states of the United States (US) for the period 1976-2017 using a number of state-of-the-art unit root tests. The new developments incorporate structural break, nonlinearity, asymmetry, and cross-sectional correlation within panel-data estimation including the use of a sequential panel selection method. While not previously considered, sequential panel selection enabled us to determine and separate the stationary and nonstationary series in the sample. The empirical findings are in support of the stationarity of unemployment rate in 47 states. The findings confirm a natural rate hypothesis for the labour markets in the most US states, indicating that labour market shocks have solely temporary effects on state-level unemployment. This empirical study provides significant state-specific policy implications.
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    Article
    Hisse Senedi Getirileri, Bitcoin Getirileri ve Riskten Kaçınma Arasındaki İlişki: Çok Değişkenli Bir Garch Modelinden Kanıtlar
    (Sosyoekonomi Soc, 2021) Sivrikaya, Ayşen; İren, Perihan; Omay, Tolga
    Bu çalışma, çok değişkenli bir GARCH modeli kullanarak ABD Dow Jones Borsasında işlem gören hisse senedi getirileri, Bitcoin getirileri ve bunların belirsizlikleri arasındaki ilişkileri araştırmaktadır. Özellikle, yüksek ve düşük olmak üzere farklı risk iştahının ve getirilerde belirsizliğin yüksek olduğu dönemlerde Bitcoin ve ABD hisse senedi getirilerinin verdiği tepkileri karşılaştırmaktadır. Sonuçlar, Bitcoin getirisinin riskten kaçınılan veya yüksek belirsizliğin olduğu dönemlerde hisse senedi gibi tepki verdiğini, ancak iki getiri arasındaki ilişkinin sürdürülebilir olmadığını göstermektedir. Öte yandan, ABD borsa yatırımcıları tüm örneklem dönemi boyunca riskten kaçınma davranışını gösterirken, Bitcoin yatırımcıları aynı davranışı göstermemektedir.
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    Article
    Citation - WoS: 31
    Citation - Scopus: 35
    Fractional Unit-Root Tests Allowing for a Fractional Frequency Flexible Fourier Form Trend: Predictability of Covid-19
    (Springer, 2021) Omay, Tolga; Baleanu, Dumitru
    In this study we propose a fractional frequency flexible Fourier form fractionally integrated ADF unit-root test, which combines the fractional integration and nonlinear trend as a form of the Fourier function. We provide the asymptotics of the newly proposed test and investigate its small-sample properties. Moreover, we show the best estimators for both fractional frequency and fractional difference operator for our newly proposed test. Finally, an empirical study demonstrates that not considering the structural break and fractional integration simultaneously in the testing process may lead to misleading results about the stochastic behavior of the Covid-19 pandemic.
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    Article
    Representation of Omitted Variable Bias With the Total Derivative Method
    (Universal Wiser Publisher, 2024) Omay, Tolga; Elitas, Zeynep
    This study aims to provide an understanding of the concept of omitted variable bias through the total derivative method. This novel approach that is often overlooked could bring a new perspective to statisticians, econometricians, or researchers in neighboring disciplines such as social sciences, management, or economics. In order to complement this mathematical method, the study also employs graphical representations. By doing so, we provide a detailed walkthrough of the total derivative method, its visual depiction, and its application to the omitted variable bias. We believe that this approach can enhance the understanding of regression analysis and foster a deeper connection between mathematics and econometrics. Overall, this study can contribute to the development of new theoretical foundations using the total differential method in this context.
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    Conference Object
    Citation - Scopus: 2
    Fiscal Sustainability From a Nonlinear Framework: Evidence From 14 European Countries
    (Springer Science and Business Media B.V., 2019) Hasdemir,E.; Omay,T.
    This study examines the fiscal sustainability of 14 European Union (EU) Member countries in the long run. For this purpose, a linear Augmented Dickey Fuller (ADF) and a variety of nonlinear univariate unit root tests are applied to the debt-to-GDP series of the 14 EU Member countries; Belgium, Czech Republic, Denmark, Finland, France, Greece, Hungary, Italy, Netherlands, Poland, Portugal, Romania, Slovakia and Sweden. In addition to that, the nonlinear unit root tests applied in this study are classified according to the source of nonlinearities: (i) time dependent nonlinearity (structural break(s)), (ii) state dependent nonlinearity and (iii) hybrid nonlinearity. Thus, the nonlinearities and their sources in data generating process of debt-to-GDP series of every country can be determined. The findings of this study show that the null of linear unit root cannot be rejected for none of the countries by applying linear ADF whereas it can be rejected as a result of nonlinear unit root tests for considerable number of countries, i.e. 11 out of 14 countries exhibit time dependent nonlinearity, 6 out of 14 exhibit state dependent nonlinearity and 10 out of 14 exhibit hybrid nonlinearity in their relevant data. So, the source of nonlinearities in the relevant data differs according to the country. That is, for testing the fiscal sustainability, the nonlinearities in the data need to be taken into account. Ignoring the nonlinearities in the testing procedure can lead misleading results in the decision of fiscal sustainability in the long run. © 2019, Springer Nature Switzerland AG.