2.4. Statistical Analyses
REGRESSION
R statistical environment (ver. 3.6.2, R Foundation for Statistical Computing, Vienna, Austria), was used for data operations, reported data analyses and visualizations. The data.table library was used for carrying out operations on data. Elementary R functions, ggplot2 and bayesplot libraries were used for plotting graphs [By employing two information criteria established with the cross-validation method—the leave-one-out information criterion (LOOIC) and the k-fold information criterion (KFOLDIC)—researchers compared predictive power of the estimated regression models. Both statistics are used to measure a model’s predictive power outside the sample, i.e., the model’s ability to accurately forecast new observations. Because the LOOIC and KFOLDIC values are based on logarithms of probability, discrepancies in their values always imply compelling evidence in favor of the better model. This can be explained by the fact that discrepancies between 110 and 100 and between 1010 and 1000 are considered equally compelling evidence—10 units, regardless of the baseline statistics—in favor of the better-fitted model. The LOOIC was the default statistic. Nevertheless, if the LOOIC approximation was unreliable, KFOLDIC was applied [