İktisat Bölümü Yayın Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/402

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Author: search.filters.author.Yazici, MehmetHas files: No

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Now showing 1 - 6 of 6
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Model Selection Uncertainties and Model Averaging in Autoregressive Time Series Models
    (Isoss Publ, 2012) Islam, M. Qamarul; Yazıcı, Mehmet; Yazici, Mehmet; Islam, M.Qamarul; Qamarul Islam, M.; İktisat
    Selecting the correct lag order is necessary in order to avoid model specification errors in autoregressive (AR) time series models. Here we explore the problem of lag order selection in such models. This study provides an in-depth but easy understanding of the model selection mechanism to the practitioners in various fields of applied research. Several interesting findings are reported and through these the pitfalls of the model selection procedures are exposed. In particular, we show that the whole exercise of model selection and subsequent statistical inference invariably depends upon unknown entities, namely the true values of parameters in the model. The model averaging technique is proposed as an alternative to the common practice of model selection and it is shown that, as a result, the properties of post-model-selection estimates substantially improve.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 1
    Impact of Exchange Rate and Customs Union on Trade Balance at Commodity Level of Turkey With Eu (15)
    (Routledge Journals, Taylor & Francis Ltd, 2011) Islam, M. Qamarul; Yazici, Mehmet; Qamarul Islam, M.
    This paper investigates the short-run and long-run impact of exchange rate and customs union on the trade balance at commodity-group level of Turkey with EU (15). Bounds testing approach is employed where a new strategy in the model selection phase is odopted ensuring that optimal model is selected from those models satisfying both diagnostics and cointegration. Results indicate that in the short-run exchange rate matters in determination of trade balance of 13 commodity groups out of 21 and customs union in 8 cases. Pattern of response of trade balance to exchange rate does not suggest a J-curve effect in any of cases. As for the long-run effect, neither exchange rate nor customs union has a statistically significant effect on trade balance of any of commodity groups, suggesting that those significant short-run effects don't last into long-run.
  • Article
    Citation - Scopus: 1
    Real Exchange Rates and Job Flows: Evidence From Turkey
    (Routledge Journals, Taylor & Francis Ltd, 2018) Islam, M. Qamarul; Yazici, Mehmet; Dogan, Ergun
    This study investigates the effects of the real exchange rate on job flows in Turkish manufacturing industries between 2006 and 2015 using data at the four-digit NACE Revision 2 level. Using dynamic panel data models, we find that a real appreciation increases gross and net job creation rates, and that the effect of appreciation is magnified as the exposure to international competitiveness of industries increases. We think that this is because Turkish manufacturing firms import a greater share of their inputs compared to the firms in developed countries. Hence, an appreciation creates more jobs because lower imported input costs enable firms to outcompete foreign producers.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 11
    Firm Size and Job Creation: Evidence From Turkey
    (Routledge Journals, Taylor & Francis Ltd, 2017) Islam, M. Qamarul; Yazici, Mehmet; Dogan, Ergun
    This study examines the relationship between firm size and job creation by using an extensive data set covering all non-farm Turkish businesses with 20 or more employees from 2003 to 2010. We find that small firms (firms with employees between 20 and 100 employees) have higher mean job flow rates (job creation, job destruction and net job creation rates) than large firms. Firm size and job flow rates are inversely related, and this relationship is especially prominent for firms with 50 employees or more. Although the overall pattern observed is also observed in both sectors, job creation rates in services are higher than the ones in manufacturing. The magnitudes of job destruction rates are comparable across sectors. Higher job creation rate in services but comparable job destruction rate results in higher net job creation rate in services. As for shares, only for smaller firms (20-49 and 50-99 size categories), job creation shares are greater than their shares in employment. But these firms have disproportionate job destruction shares as well. We also find that only the 20-49 category firms contribute to net job creation more than their share in employment. The smaller firms have high disproportionate shares in job creation and destruction in manufacturing and services as well.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Inference in Multivariate Linear Regression Models With Elliptically Distributed Errors
    (Taylor & Francis Ltd, 2014) Yazici, Mehmet; Islam, M. Qamarul; Yildirim, Fetih
    In this study we investigate the problem of estimation and testing of hypotheses in multivariate linear regression models when the errors involved are assumed to be non-normally distributed. We consider the class of heavy-tailed distributions for this purpose. Although our method is applicable for any distribution in this class, we take the multivariate t-distribution for illustration. This distribution has applications in many fields of applied research such as Economics, Business, and Finance. For estimation purpose, we use the modified maximum likelihood method in order to get the so-called modified maximum likelihood estimates that are obtained in a closed form. We show that these estimates are substantially more efficient than least-square estimates. They are also found to be robust to reasonable deviations from the assumed distribution and also many data anomalies such as the presence of outliers in the sample, etc. We further provide test statistics for testing the relevant hypothesis regarding the regression coefficients.
  • Article
    Turkish Agricultural Import and Export Demand Functions: Estimates From Bounds Testing Approach
    (Routledge Journals, Taylor & Francis Ltd, 2012) Yazici, Mehmet
    This paper estimates the import and export demand functions for Turkish Agriculture based on the annual data for 1970-2003. The bounds testing approach to the cointegration and the error correction modeling is employed. We, however, adopt a new strategy in the model selection phase and select the optimal model from those models that satisfy both diagnostics and cointegration, thus, unlike the previous literature, ensuring that a statistically reliable and cointegrated model is picked up. Results indicate that for the import demand, relative price is a significant determinant in both short-run and long-run, nominal effective exchange rate matters only in the long-run, but domestic income is not at all a significant determinant for Turkish agricultural import demand. As for the export demand, while all determinants affect the export demand significantly in the short-run, given the relatively small share of Turkish agricultural exports within the world agricultural exports, none individually matters in the long-run.