1. Maria Garcia US Census Bureau UNECE/SDE, Oslo, Norway, 24-26 September 2012 An Application of Selective Editing to the US Census Bureau Trade Data

2. Foreign Trade Statistics Programs Official source of US international merchandise trade statistics Electronic data collection Complete enumeration Pre – editing: check for fatal errors Micro editing –Range and ratio edits –Automatic imputation –“Rejects” – imputation not successful

3. Foreign Trade Data Processing Rejects –Distribute among analysts for manual correction. –Analysts review large number of records under tight time constraints Goal: Use selective editing to identify highly suspicious errors having a high potential effect on the estimates –Value (V) –Quantity (Q) –Shipping weight (SW)

4. Hidiroglou-Berthelot Method (HB)

5. HB Method for Our Trade Data

6. HB for Our Trade Data (Cont’d)

7. Effect on Publication Totals

8. Simulation and Evaluation

9. Evaluation Results Examining results at lowest level of aggregation: –Data users may closely scrutinize the statistics for particular types of products –Ex: import/export of rough diamonds –Kimberley Process - joint governments, industry and civil society initiative to stem the flow of conflict diamonds

10. Evaluation Results

12. Customer’s Feedback Subject matter experts questioned: –High ranking given to records that by experience they consider insignificant to final cell estimates –Low ranking given to records that would have been flagged for manual correction

13. Total Value (V) Total Quantity (Q) Unit Price (V/Q) Ratio Bounds Reported cell total $102,1907,217$14.15903000 Reported suspicious Record $3,024 7,144$0.42903000 Final suspicious record $3,02410$302.40903000 Final cell total $102,19083$1,231.20903000 Commodity XXXXXXXXXX Customer’s Feedback

14. Total Value (V) Total Quantity (Q) Unit Price (V/Q) Ratio Bounds Lower Bound Upper Bound 128 records, 87 records imputed, three rejects $3,142,622129,973,502$0.020.2550 Final cell total All three rejects corrected $3,142,6221,230,629$2.550.2550 Selective editing cell total Two highest ranked records corrected $3,142,6221,804,699$1.740.2550 Commodity YYYYYYYYYY Customer’s Feedback

15. Concluding Remarks

16. Thank you!