Thanks to Kit Baum, three utilities for easy manipulation of timespan data
(and the creation of a repeated cross-section) are now available through SSC:
. ssc d spellutil
I attach for those interested a small illustration below.
Hope this is useful (and not a duplication of something already in stata or
out there)
Thanks, Ed.
. use t, clear
. cl
id jobid date0 date1 hours wage
1. 1 1 01Jan2000 03Mar2000 30 10
2. 1 1 04Mar2000 01Sep2000 30 10
3. 1 2 01May2000 01Aug2000 15 12
. spellmerge, spell(date0 date1) gap(1) by(id jobid)
. cl
id jobid date0 date1 hours wage
1. 1 1 01Jan2000 01Sep2000 30 10
2. 1 2 01May2000 01Aug2000 15 12
. spellsplit (sum) hours (mean) wage, spell(date0 date1) by(id)
. cl
id date0 date1 wage hours _count
1. 1 01Jan2000 01May2000 10 30 1
2. 1 01May2000 01Aug2000 11 45 2
3. 1 01Aug2000 01Sep2000 10 30 1
. drop _count
. spell2panel wage hours, spell(date0 date1) by(id) p(m)
. cl
id wage hours _m _length
1. 1 10 30 2000m1 31
2. 1 10 30 2000m2 29
3. 1 10 30 2000m3 31
4. 1 10 30 2000m4 30
5. 1 11 45 2000m5 31
6. 1 11 45 2000m6 30
7. 1 11 45 2000m7 31
8. 1 10 30 2000m8 31
or more quickly, just type
. spell2panel (mean) wage (sum) hours, spell(date0 date1) by(id) p(m)
*
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