1[2 {"id":"C1","text":"The seasonal AR model has lower out-of-sample RMSE than seasonal-naive at h=1, 2 and 4 (relative improvements 0.230, 0.135, 0.187).","results_keys":["rmse_snaive_h1","rmse_model_h1","rmse_snaive_h2","rmse_model_h2","rmse_snaive_h4","rmse_model_h4","rel_improvement_rmse_h1","rel_improvement_rmse_h2","rel_improvement_rmse_h4"],"status":"supported","caveat":"Point estimates over 40 origins; no formal test at h=1,2; window dominated by 2020-2022 shocks."},3 {"id":"C2","text":"The model also has lower MAE than seasonal-naive at all three horizons.","results_keys":["mae_snaive_h1","mae_model_h1","mae_snaive_h2","mae_model_h2","mae_snaive_h4","mae_model_h4"],"status":"supported","caveat":"Point estimates only."},4 {"id":"C3","text":"At h=4 the mean squared-error loss differential (2.82, model better) is not statistically distinguishable from zero with a Bartlett HAC SE at lag 4 (DM=1.52, p=0.128).","results_keys":["loss_diff_mean_h4","loss_diff_se_h4","hac_lags_h4","hac_kernel_h4","dm_stat_h4","dm_pvalue_h4"],"status":"supported","caveat":"Sensitive to HAC choice: p ranges 0.041 (Bartlett lag 6) to 0.177 (Bartlett lag 3); see sensitivity_h4. Small T=40, asymptotic normal reference."},5 {"id":"C4","text":"The h=4 test conclusion is not robust to the HAC truncation lag; only a non-prespecified longer lag (6) yields p<0.05.","results_keys":["sensitivity_h4"],"status":"supported","caveat":"Supplementary analysis; driven by negative autocorrelation of d_t at lags 3-4."}6]7