Identifying Trend and Age Effects in Sickness Absence from Individual Data: Some Econometric Problems
When using data from individuals who are in the labour force to disentangle the empirical relevance of cohort, age and time effects for sickness absence, the inference may be biased, affected by sorting-out mechanisms. One reason is unobserved heterogeneity potentially affecting both health status and ability to work, which can bias inference because the individuals entering the data set are conditional on being in the labour force. Can this sample selection be adequately handled by attaching unobserved heterogeneity to non-structured fixed effects? In the paper we examine this issue and discuss the econometric setup for identifying from such data time effects in sickness absence. The inference and interpretation problem is caused, on the one hand, by the occurrence of time, cohort and age effects also in the labour market participation, on the other hand by correlation between unobserved heterogeneity in health status and in ability to work. We show that running panel data regressions, ordinary or logistic, of sickness absence data on certain covariates, when neglecting this sample selection, is likely to obscure the interpretation of the results, except in certain, not particularly realistic, cases. However, the fixed individual effects approach is more robust in this respect than an approach controlling for fixed cohort effects only.
|Date of creation:||18 Dec 2010|
|Date of revision:|
|Contact details of provider:|| Postal: |
Phone: 22 85 51 27
Fax: 22 85 50 35
Web page: http://www.oekonomi.uio.no/indexe.html
More information through EDIRC
When requesting a correction, please mention this item's handle: RePEc:hhs:osloec:2010_020. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Rhiana Bergh-Seeley)
If references are entirely missing, you can add them using this form.