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EN
In the following article the authors describe the problem of influence of a sample size and a method of handling missing values on the results and goodness of fit of the path relation model. In order to estimate the goodness of fit of the model the authors use the indicators which describe the internal (Cronbach’s Alfa, Composite Reliability) and external (R2) stability of the model. By the term “results of the models” the authors mean estimated index values for latent variables and path coefficients of the SEM modeling procedure. In the research the authors analysed outcomes of Partial Least Squares method, used to build a model of Lublin shopping malls sector customers’ satisfaction and loyalty. The research included 43 datasets that varied in a number of observations and a method used for solving the missing values problem. Obtained results not only allowed the authors to statistically verify the main research problem of the study, but also enabled researchers to evaluate practical applicability of the analyzed imputation methods in real market and business consultancy activities. The research showed the supremacy of the Predictive Mean Matching and CART algorithms over other methods in the majority of analyzed ceases. Nevertheless, the differences between obtained results were rather insignificant, so one may assume that there is no visible influence of the used method on the practical interpretation of the obtained model and analyzed phenomenon.
PL
W pracy przedstawiono metodę modelowania a następnie prognozowania w sytuacji, gdy w szeregu czasowym dla danych dziennych występują luki systematyczne. Podstawą budowy prognoz były regularne hierarchiczne modele szeregu czasowego opisujące wahania o rocznym. Wahania o cyklu tygodniowym były opisywane za pomocą zmiennej grupującej, w skład której wchodziły dni podobne oraz tego rodzaju zmiennych dla pozostałych dni. W modelach wystąpiły także zmienne o charakterze migawkowym oznaczające występowanie świąt oraz dni około świątecznych. Rozważania o charakterze teoretyczne zostały zilustrowane przykładem empirycznym dla założonego wariantu luk w danych. Przeprowadzona została analiza dokładności błędów prognoz intern ekstrapolacyjnych ogółem oraz w dezagregacji na dni tygodnia, miesiące i święta oraz dni około świąteczne.
EN
This paper presents a method for modeling and then forecasting in situation, when in time series for daily data contain systematic gaps. Base of construction were regular hierarchical time series models describing annual fluctuations. Weekly fluctuations were described as a grouping variable, which contains similar days and this type variables for other days. In models were used also dummy variables describing holidays and days pre- and post- holidays. Theoretical considerations were illustrated by empirical example for selected variant of gaps. Based on the same estimated equations, inter- and extrapolation predictions ware built. For both types of prediction – in general and in disaggregation to weekdays and months and holidays and days pre- and post holidays.
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