Backward recalculation of seasonal series affected by economic crisis: a Model-Based-Link method for the case of Turkish GDP

When attempting to deal with the recalculation process, it is hard to answer the question “Does the recalculated series include economic events and seasonal behaviours in the past?”. This paper discusses some alternative backward recalculation methods and presents the applications and their results relative to the Turkish Gross Domestic Product (GDP) series. Using comparative analysis, it is shown that ordinary ARIMA forecasts and signal extraction methods are not successful at taking into account past events in the backward recalculated series. A new innovative method, named Modelbased-link, is then proposed and suggested by the authors in order to be able to take past economic events and seasonal patterns into account when the series is to be backward recalculated. A first application of this new method is run on the quarterly series of the Turkish GDP. In addition, it is shown that the Model-based-link method can be extended to data sets of different frequencies (i.e. annual data). Consequently, it can be claimed that a comparable recalculated quarterly and annual Turkish GDP series for forthcoming data is obtained. The paper is structured as following: section 1 introduces the reader to the state of the art in the current literature; section 2 defines the information set to be backward recalculated and presents some statistics on the data while section 3 presents the main methodological statistical aspects of classical methods compared to the methodological scheme of the Model-based-link that can be used for the recalculation process. Section 4 presents results of the methods mentioned in the previous section and section 5 discusses the extension of the Model-based-link method to monthly data and includes an application for annual data; section 6 concludes. Finally, section 7 presents topics for discussion and challenges for continuation of the analysis

Sanayi Uretiminde Tatil Etkileri

Omitting the official and religious holidays which are deterministic components of a time series causes a bias on analyzing of economic time series and this biased series comparisons will be at fault. In this study, I will discuss how the holiday variables can be constructed and analyzed in Turkish industrial production index (2005=100). I will also discuss how this effect adjust from original series and interpretation of this effects. According to application results achieved by RegARIMA model, it is carried out moving holidays have negative and statistical signifact effects on industrial production index. In addition, it is found out that rather than level of series, holiday effects makes an unignorable difference on growth rate of series.Time Series Decomposition, Stochastic Components, Deterministic Components, Holiday Effects, Religious Holidays, SARIMA, RegARIMA, Airline Model

Backward recalculation of seasonal series affected by economic crisis: a Model-Based-Link method for the case of Turkish GDP

When attempting to deal with the recalculation process, it is hard to answer the question “Does the recalculated series include economic events and seasonal behaviours in the past?”. This paper discusses some alternative backward recalculation methods and presents the applications and their results relative to the Turkish Gross Domestic Product (GDP) series. Using comparative analysis, it is shown that ordinary ARIMA forecasts and signal extraction methods are not successful at taking into account past events in the backward recalculated series. A new innovative method, named Modelbased-link, is then proposed and suggested by the authors in order to be able to take past economic events and seasonal patterns into account when the series is to be backward recalculated. A first application of this new method is run on the quarterly series of the Turkish GDP. In addition, it is shown that the Model-based-link method can be extended to data sets of different frequencies (i.e. annual data). Consequently, it can be claimed that a comparable recalculated quarterly and annual Turkish GDP series for forthcoming data is obtained. The paper is structured as following: section 1 introduces the reader to the state of the art in the current literature; section 2 defines the information set to be backward recalculated and presents some statistics on the data while section 3 presents the main methodological statistical aspects of classical methods compared to the methodological scheme of the Model-based-link that can be used for the recalculation process. Section 4 presents results of the methods mentioned in the previous section and section 5 discusses the extension of the Model-based-link method to monthly data and includes an application for annual data; section 6 concludes. Finally, section 7 presents topics for discussion and challenges for continuation of the analysis

Filtering Short Term Fluctuations in Inflation Analysis

Many economic time series, specifically inflation, are inherently subject to seasonal fluctuations which obscure the real changes of the series. In this respect, seasonal adjustment is a powerful tool when removing such fluctuations. On the other hand, seasonal adjustment may provide highly volatile series, making it still difficult to interpret the movements of the series. The reason is that seasonal adjustment deals with certain type of movements that are completed on specific seasonal frequencies. However, it is possible that there may be other short term fluctuations occurring at non seasonal frequencies. From this observation and in the context of inflation, an improved methodology aiming to deal with all short term fluctuations that are completed within a year is proposed in this study. The two-step approach combines wavelet filters and band pass filters. This method yields much smoother time series than seasonal adjustment does. Moreover, the filtered series capture the dynamics of the inflation in sub groups well. Hence, this two-step procedure provides a useful tool for improved short term inflation analysis.Consumer prices, inflation, seasonal adjustment, wavelet filter, band pass filter

A long-term multicenter study: Entecavir versus Tenofovir in treatment of nucleos(t)ide analogue-naive chronic hepatitis B patients

Background: Entecavir (ETV) and tenofovir disoproxil fumarat (TDF) are the two first-line therapies recommended in the treatment of chronic hepatitis B because of having potent antiviral effect and high genetic barriers against resistance. We aimed to compare efficacy of these drugs and to evaluate predictors of viral suppression

Rapid Emergency Medicine Score and HOTEL Score in Geriatric Patients Admitted to the Emergency Department

Background: Emergency risk scoring systems have been defined in order to identify the health status of the patients on admission to the emergency department. In this study, we aimed to investigate the prognostic values of Rapid Emergency Medicine Score (REMS), REMS without age and the HOTEL scores in geriatric patients. Methods: This prospective, single-centered, observational study was carried out between the January 15, 2014 February 28, 2014. Patients admitted to the emergency department during the study period and aged 65 years or older were included in the study. Results: In total, 939 patients were included in the study. In predicting the intensive care unit admission, the area under the curve values of the REMS, REMS without age, and HOTEL scores were 0.772, 0.760, and 0.827 (p < 0.001, for all), respectively. The median (interquartile range) REMS and REMS without age scores of the nonsurvivors were statistically significantly higher than those of the survivors {[}10 (6) vs. 6 (3), 5 (6) vs. 1(2), respectively; p < 0.001 for both]. Similarly, the HOTEL scores of the nonsurvivors were also statistically significantly higher than those of the survivors {[}2 (1) vs. 1(1), p < 0.001]. In predicting the in-hospital mortality, the area under the curve values of the REMS, REMS without age and HOTEL scores were 0.833, 0.819, and 0.858 (p < 0.001 for all), respectively. Conclusion: The REMS, REMS without age, and the HOTEL scores cannot be efficiently employed to discriminate geriatric patients requiring hospitalization. Nonetheless, all three scores are proper predictive systems regarding intensive care unit admission and in-hospital mortality in geriatric emergency department patients. Copyright (C) 2015, Taiwan Society of Geriatric Emergency \& Critical Care Medicine. Published by Elsevier Taiwan LLC. All rights reserved