1. Revision of Error Margins (point for decision)
Mathieu Erzar
2-3 April 2009
Meeting of the Working Group on Rail Transport Statistics
Agenda point: 7.3 Doc Rail

2. Aim and current situation
General aim of the margins
Detection of extraordinary growth rates between two consecutive years
Verification of the credibility of the records with the concerned country
Current situation
Same margins applied for all datasets
100% change for Warnings
300% change for Errors
2-3 April 2009
Meeting of the Working Group on Rail Transport Statistics
Agenda point: 7.3 Doc Rail

3. Definition of new margins
Aims of the new “error margins”
New error margins taking into account the specificity of the various datasets
Reduction of the burden of the countries
Methodology
For the low absolute values: more tolerance (increase of the error margins threshold)
For the high absolute values: decrease of the error margins threshold
Focus on the most important problems
“Warning thresholds” to be taken out
2-3 April 2009
Meeting of the Working Group on Rail Transport Statistics
Agenda point: 7.3 Doc Rail

4. Example of application of the new margins proposed
Number of loaded ITUs
YEAR
COUNTRY A
COUNTRY B
Y-1
47 500
40 000 Y
66 200
70 000
Change
39%
75%
Higher values ( and ) included in the interval [50 000;Max]
Example of records provided by reporting countries A and B
Extract of the table with the new margins (full table available on p.8 of the WG document 6)
COUNTRY A
Growth rate (39%) lower than 55%
The threshold is not reached
(no clarification needed from the country)
2-3 April 2009
Meeting of the Working Group on Rail Transport Statistics
Agenda point: 7.3 Doc Rail

5. Example of application of the new margins proposed
Number of loaded ITUs
YEAR
COUNTRY A
COUNTRY B
Y-1
47 500
40 000 Y
66 200
70 000
Change
39%
75%
Higher values ( and ) included in the interval [50 000;Max]
Example of records provided by reporting countries A and B
Extract of the table with the new margins (full table available on p.8 of the WG document 6)
COUNTRY B
Growth rate (75%) is higher than 55%
The threshold is reached
(clarification needed from the country)
2-3 April 2009
Meeting of the Working Group on Rail Transport Statistics
Agenda point: 7.3 Doc Rail

6. Summary & proposal The new margins will:
Take into account the specificity of the datasets
Focus on the main problems
Reduce the burden of the countries
Errors for Annexes A to E datasets and Alerts for
Annex H datasets
New approach beneficial for Eurostat and the countries
Proposal: Replacement of warning and error thresholds (of 100% and 300%) by a new set of error (and alert) margins only (see new thresholds defined in WG doc. 6)
2-3 April 2009
Meeting of the Working Group on Rail Transport Statistics
Agenda point: 7.3 Doc Rail

7. The Member States are kindly requested
to express their position on the new error margins settings proposed by Eurostat
Thank you for your attention !
2-3 April 2009
Meeting of the Working Group on Rail Transport Statistics
Agenda point: 7.3 Doc Rail