Is the data adjusted for inflation? The real versus nominal figures would tell very different stories.
Dana Gruber The Barcelona revision in 2019 was stated as a 6% adjustment, but the documentation doesn't say whether it was a correction of error, a redefinition, or a methodological improvement. The type of revision matters: error corrections suggest past figures were wrong, while redefinitions suggest they measured something different. Should we clarify which it was?
I notice that the seasonal decomposition was recalibrated in 2018, which means the seasonal factors and residuals for 2015-2017 are computed differently from 2018 onward. This creates a subtle but material comparability issue: adjusted series are not directly comparable across the 2017-2018 boundary. Should we recompute the entire seasonal decomposition using a single model?
Yes, exactly this.