Round Table on Time Series Some Remarks berthold

Round Table on Time Series Some Remarks berthold. feldmann@ec. europa. eu Eurostat

Data exchange n Where does the data come from? Ü All regional data come from National Statistical Offices Ü Urban Audit data comes from NSOs and cities n Do you have control over the data flow? Ü Yes, data is transmitted following an agreed data protocol (e. Damis) n Can you modify the data? Ü Yes, we modify incorrect data and fill gaps of missing data Ü In each such case the NSO concerned is informed 2/6 Supply and demand of regional statistics

Filling gaps of missing data n What methods do you use to fill the gaps? Ü We don’t have the human resources to estimate missing data ourselves Ü For complex estimations we use contractual work Ü For quick and dirty estimations we interpolate or use older data to which we apply the growth rate of a larger (national) aggregate n How do you extrapolate data? Ü Eurostat does not do any forecast at all 3/6 Supply and demand of regional statistics

Outlier detection n How do you check for outliers? Ü So far we only check for outliers in Urban Audit data, not in the regional data set Ü We have a complex algorithm to check for outliers, mainly looking for values beyond x times the standard deviation from the median (assuming a normal distribution) Ü The x varies depending on the analysed statistics Ü Sometimes we take only a subset of cities, for example cities in New Member States 4/6 Supply and demand of regional statistics

Meta Data n Do you indicate which data is original and which is estimated? Ü Yes, this is clarified with a flag n Do you indicate which data is exceptional or suspect? Ü Eurostat does not publish exceptional or suspect data n Do you propose tools for self estimation to users? Ü no 5/6 Supply and demand of regional statistics

Thank you for your attention! Any questions? 6/6 Supply and demand of regional statistics