Dear statalisters,
I have a sample of duration data on unemployment. The sample shares characteristics of stock and flow sample selection. That is, I have all persons that where unemployed between 1 january 1999 and 1 january 2007; including those who have been unemployed before 1 january 1999 and still unemployed between 1999 and 2007 as well as new entrants who became unemployed somewhere between 1999 and 2007.
For estimation I use the specification of Jenkins for discrete duration data where spells are converted to spell months and estimating proceeds by estimation of binary data. My question is whether for those who were already unemployed before 1999, I should condition the likelihood as described by Jenkins. If so, how should I do this?
Kind regards,
Marcel
_________________________________________________________________
Express yourself instantly with MSN Messenger! Download today it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/