Results of the addition study in the three regions: Algorithm 1 with Poisson for f and identity for g, , , , and . We denote by w: situation in the test period with the added variable and wo: situation in the test period without the indicated variable. Ratios of w/wo are reported. Note that, for the metrics such as RMSE, MASE and MARE, a ratio lower than 1 implies an improvement of the model when the variable is added as an explanatory variable. A ratio of higher than 1 indicates that adding the variable improves the forecasts.