Estimating the non-response bias using exogenous data on employment Etienne Debauche Corinne Prost

1. Estimating the non-response bias using exogenous data on employment Etienne Debauche Corinne Prost

2. Response rate in the French LFS • large variability in space and in time • special event in 2007

3. Response rate in the French LFS • non-response survey: • « light » PAPI survey, sent to the non-respondents • around 20% of the non-respondents answer to this survey • they are more often employed than the respondents of the main survey • question: is the correction of non-response in the weighting scheme efficient enough to correct for non-response bias?

4. Response rate in the French LFS • one study done in 2007: very small effect of the response rate on the measure of the unemployment rate • geographical analysis • problem: the response rate is endogenous: employment rate and response rate are both impacted by the business cycle

5. Employment in the French LFS • Employment: differences between the LFS estimate and the official employment estimate, coming from administrative database

6. Employment in the French LFS • a lot of reasons why both estimates are different: • concepts: ILO employment / job statistics; differences for sick leaves, maternity or paternity leaves • scope: total employment / private employment; frontier workers; collective households • quarterly average / average of the number of jobs at the end of the quarters • And errors in the LFS: sampling errors; non-response bias; bias due to the proxy answerings 

7. Modeling the non-response rate • behavior of the interviewers: they start with easier interviewees (for instance non-active ones). They stop when the cost of search exceeds the benefit. C n

8. Using the administrative data employment estimates to assess the non-response bias Response rate: Administrative data employment: LFS employment:

9. Using the administrative data employment estimates to assess the non-response bias

10. Using the administrative data employment estimates to assess the non-response bias • estimation at the region level (NUTS2 and NUTS3), with region and time fixed effects: the effect of the response rate is identified within the regions, independently of the national business cycle • estimation on the employment rates • weight: population of the region

11. Effect of the response rate

12. Effect of the response rate • robustness check thanks to the natural experiment of 2007: the increase of the response rate on 2007 is due to the controversy. It should be exogenous.

13. Effect of the response rate

14. Conclusion • There is a significant effect; can the correction for non-response be improved? • The effect is not large. In particular, it only explains a small part of the discrepancies between LFS employment and administrative data employment. Can the other sources of discrepancies be quantified?

15. Discussion • similar results in other countries? • do some countries use external administrative data employment in the weighting scheme (grossing factor)?