Ekonomi Bölümü yayınlarını içerir. http://hdl.handle.net/20.500.12416/818 2026-10-28T17:59:45Z 2026-10-28T17:59:45Z Çorakçı, Ayşegül Omay, Tolga http://hdl.handle.net/20.500.12416/8480 2024-06-05T11:00:26Z 2023-03-01T00:00:00Z

Is there convergence in renewable energy deployment? Evidence from a new panel unit root test with smooth and sharp structural breaks Çorakçı, Ayşegül; 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 economies to seek out the menu of policies that ensure the worldwide success of renewable energy transformation.

2023-03-01T00:00:00Z Omay, Tolga Çorakçı, Ayşegül http://hdl.handle.net/20.500.12416/8407 2024-05-27T11:54:49Z 2023-01-01T00:00:00Z

A Unit Root Test with Markov Switching Deterministic Components: A Special Emphasis on Nonlinear Optimization Algorithms Omay, Tolga; Çorakçı, Ayşegül In this study, we investigate the performance of different optimization algorithms in estimating the Markov switching (MS) deterministic components of the traditional ADF test. For this purpose, we consider Broyden, Fletcher, Goldfarb, and Shanno (BFGS), Berndt, Hall, Hall, Hausman (BHHH), Simplex, Genetic, and Expectation-Maximization (EM) algorithms. The simulation studies show that the Simplex method has significant advantages over the other commonly used hill-climbing methods and EM. It gives unbiased estimates of the MS deterministic components of the ADF unit root test and delivers good size and power properties. When Hamilton’s (Econometrica 57:357–384, 1989) MS model is re-evaluated in conjunction with the alternative algorithms, we furthermore show that Simplex converges to the global optima in stationary MS models with remarkably high precision and even when convergence criterion is raised, or initial values are altered. These advantages of the Simplex routine in MS models allow us to contribute to the current literature. First, we produce the exact critical values of the generalized ADF unit root test with MS breaks in trends. Second, we derive the asymptotic distribution of this test and provide its invariance feature. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

2023-01-01T00:00:00Z Doğan, Ergun Zhang, Xibin http://hdl.handle.net/20.500.12416/8402 2024-05-27T11:53:56Z 2023-11-01T00:00:00Z

A nonparametric panel data model for examining the contribution of tourism to economic growth Doğan, Ergun; Zhang, Xibin We apply a nonparametric panel data model with cross-sectional and time-varying coefficients to examine the relationship between tourist arrivals and economic growth in the Schengen area from 1995 to 2019. In contrast to the parametric models employed in other studies, our nonparametric model makes no assumption about functional form and, hence, allows us to model the relationship nonlinearly. We find that the tourism–economic growth relationship in the Schengen area is nonlinear and time-varying. While the relationship between tourism and economic growth was positive and significant during 1995–2003, it was negative and significant during the Global Financial Crisis (2007–2008) and the European recession of 2012–2013. One additional contribution of the study is the finding that total factor productivity (TFP) has been growing at 1.45% per year. The results also show that country-level TFP growth was disrupted during the aforementioned negative economic shocks.

2023-11-01T00:00:00Z Eruygur, Ayşegül http://hdl.handle.net/20.500.12416/8208 2024-05-08T08:29:21Z 2011-01-01T00:00:00Z

The New Keynesian Phillips curve: in search of improvements for Adaptation to the Turkish economy Eruygur, Ayşegül Bu makalede oldukça geniş olan Yeni Keynesgil Phillips Eğrisi literatürü; hem teorik hem de ampirik açıdan bir çok tartışmayı gözler önüne serecek biçimde incelenmiştir. Yeni Keynesgil Phillips Eğrisi’nin Türkiye uygulamaları bu eğrinin Türkiye’ye uygulanabilirliği ve geçerliliğiyle ilgili oldukça çelişkili sonuçlar vermektedir. Bu çelişkili sonuçlar özellikle, bu çalışmalarda Türkiye’nin önemli yapısal özelliklerinin göz ardı edilmesine ve açık ekonomiyi tanımlayan etmenlerin Yeni Keynesgil Phillips Eğrisi’ne dahil ediliş şekline göre oluşan farklı model yapılarına atfedilmiştir. Türkiye’ye uygulanacak bir Yeni Keynesgil Phillips Eğrisi modelinde, ithal ara malları içeren bir üretim fonksiyonu, ithal mallarda tamolmayan döviz kuru geçişkenliği ile birleştirilmelidir. Ampirik bulgular ithal malı fiyatlarına kur geçişkenliğinin tam olmadığını gösterdikleri halde; Türkiye için yapılmış çalışmaların hiçbirinde bu özelliğe yer verilmemiş ve dolayısıyla da ithal malı fiyatlama kararı modellenememiştir. Bunun yanı sıra, Türkiye’ye uygulanan Yeni Keynesgil Phillips Eğrisi modellerinde üretim sadece emeğin üretim faktörü olduğu doğrusal Cobb-Douglas fonksiyonu kullanılarak modellenmiştir. Halbuki Türkiye’ye ithal edilen malların çoğu ara malı düzeyindedir ve endüstrilerin üretim maliyetlerinin temelini de yine bu girdilere yapılan harcamalar oluşturmaktadır.

2011-01-01T00:00:00Z