How to create a panel of individuals observed for successive waves

[Charles Ackah]

Hi there,

I am working with a panel data of 3 waves (3, 4, and 5). I want to analyze and compare characteristics of individuals observed for successive survey waves. So, I want to create a panel for individuals observed for successive waves, i.e, a panel for those observed for wave 3 and 4; and for those observed for waves 4 and 5. My data structure is as follows:

* Example generated by -dataex-. To install: ssc    install    dataex
clear
input float hhid long pid float(wave pcy)
300000 304623 3  7.468816
300000 304624 3  7.468816
300000 304623 4  8.191607
300000 304623 5  8.257506
300000 304624 4  8.191607
300000 304624 5  8.257506
300001 305268 5  7.597524
300001 305269 4    9.4975
300001 620952 3 8.5963335
300001 305268 3 8.5963335
300001 305268 4  7.684784
300001 620952 4  7.684784
300001 305269 5  9.610334
300001 305250 5  7.597524
300001 305250 4  7.684784
300001 305269 3 8.5963335
300001 305249 5  7.597524
300001 305249 3 8.5963335
300001 305250 3 8.5963335
300001 620952 5  7.597524
300001 305249 4  7.684784
300002 319161 4  6.932395
300002 319161 5  7.663094
300002 319161 3  6.956741
300003 402779 4  6.825533
300003 309522 3         .
300003 305291 4  7.828432
300003 583034 5  8.317959
300003 402779 5  6.854149
300003 305291 3         .
300003 582536 5  6.854149
300003 309522 5         .
300003 305291 5  6.854149
300003 583034 3         .
300003 582536 4  7.828432
300003 582536 3         .
300003 309522 4         .
300003 583034 4  7.835113
300003 402779 3         .
300004 302034 5  9.338085
300004 302034 3 9.2136755
300004 302034 4  9.330969
300005 303039 4  7.448096
300005 303039 5  6.725547
300005 303039 3  9.211509
300006 305649 3  7.071443
300006 311353 4    7.9242
300006 311353 5         .
300006 311353 3  7.071443
300006 305649 5   7.90295
300006 305649 4  7.922594
300007 407393 4         .
300007 407393 3         .
300007 407397 3         .
300007 407397 5  6.300319
300007 407397 4         .
300007 407393 5  7.196711
300008 410590 5  6.955804
300008 321630 5  6.955804
300008 321630 4   6.84182
300008 410590 4   6.84182
300008 319052 4   6.84182
300008 319052 5  7.327477
300008 321631 3  7.437262
300008 319052 3  7.437262
300008 321631 5  6.955804
300008 410590 3  7.437262
300008 321631 4   6.84182
300008 321630 3  7.437262
300009 301903 5  9.647812
300009 301903 3  8.786242
300009 301903 4 10.103908
300010 409493 4  7.346483
300010 620604 3         .
300010 409494 5  7.333076
300010 381188 5  6.345164
300010 381188 3         .
300010 409494 3         .
300010 409493 5  7.333076
300010 409493 3         .
300010 620604 4   7.47222
300010 381188 4   7.47222
300010 620604 5   7.30386
300010 409494 4  7.346483
300011 470329 3         .
300011 319825 3         .
300011 319824 3         .
300011 470329 5         .
300011 319823 5         .
300011 319823 3         .
300011 319825 5         .
300011 319823 4         .
300011 319825 4         .
300011 470329 4         .
300011 319824 4         .
300011 319824 5         .
300012 720804 4   7.06202
300012 315004 3  6.578661
300012 720802 3  6.578661
300012 408582 3  6.578661
300012 407674 4  7.120476
300012 315004 5  5.729524
300012 315006 5         .
300012 720803 4   7.06202
300012 720805 3  6.578661
300012 408583 5  6.731416
300012 408582 5  6.731416
300012 315004 4   7.06202
300012 720804 3  6.578661
300012 720802 5  5.729524
300012 720804 5         .
300012 315005 4   7.06202
300012 720805 5  5.729524
300012 720802 4   7.06202
300012 408583 3  6.578661
300012 720805 4   7.06202
300012 407674 5  6.731416
300012 315005 5  5.729524
300012 720803 3  6.578661
300012 315005 3  6.578661
300012 408583 4  7.120476
300012 407674 3  6.578661
300012 408582 4  7.120476
300012 315006 3         .
300012 720803 5  5.729524
300012 315006 4         .
300013 317604 4  5.165946
300013 406032 5  6.362245
300013 406047 4  5.165946
300013 406032 4  5.165946
300013 317604 5  6.362245
300013 406032 3  7.121995
300013 406047 5  6.362245
300013 406047 3  7.121995
300013 317604 3  7.121995
300014 722781 5         .
300014 722782 5  8.229511
300014 315641 5  7.850154
300014 408664 4  7.921302
300014 722781 4         .
300014 408615 5  8.229511
300014 722782 4  7.921302
300014 315604 4         .
300014 722781 3         .
300014 408664 3  7.744731
300014 408615 3  7.744731
300014 315605 3         .
300014 408605 4  7.921302
300014 315604 5         .
300014 315641 3  7.744731
300014 315605 4         .
300014 315637 4  7.921302
300014 408605 3  7.744731
300014 315641 4  7.921302
300014 315605 5         .
300014 408605 5  7.850154
300014 408664 5  7.850154
300014 722782 3  7.744731
300014 315637 3  7.744731
300014 408615 4  7.921302
300014 315604 3  7.744731
300014 315637 5  7.850154
300015 304188 3  7.834811
300015 304185 3  7.834811
300015 730216 5         .
300015 405518 4   6.88641
300015 730216 3  7.834811
300015 304185 5  7.958376
300015 304187 4         .
300015 405518 5  7.958376
300015 730216 4         .
300015 304187 5         .
300015 405518 3  7.834811
300015 304185 4   6.88641
300015 304187 3         .
300015 304188 5  7.958376
300015 304188 4   6.88641
300016 630586 5  5.179518
300016 409643 3  5.737711
300016 409643 4  6.624718
300016 409642 5  7.942819
300016 316342 4  6.624718
300016 409642 3  5.737711
300016 316343 3  5.737711
300016 316343 5  5.179518
300016 630586 4  6.624718
300016 316342 5  5.179518
300016 409641 3  5.737711
300016 316341 4  6.624718
300016 316343 4  6.624718
300016 316342 3  5.737711
300016 409643 5  5.179518
300016 316341 3  5.737711
300016 409641 4  6.624718
300016 409642 4   7.42242
300016 630586 3  5.737711
300016 316341 5  6.985971
300016 409641 5  5.179518
300017 306543 4  6.571434
300017 403621 3   6.13646
end
label var pid "Person identifier" 
label var pcy "log per capita household income"

My xtdes command produces the following output:

xtdes

pid: 301011, 301012, ..., 799992 n = 59558
wave: 3, 4, ..., 5 T = 3
Delta(wave) = 1 unit
Span(wave) = 3 periods
(pid*wave uniquely identifies each observation)

Distribution of T_i: min 5% 25% 50% 75% 95% max
1 1 2 3 3 3 3

Freq. Percent Cum. Pattern

40558 68.10 68.10 111
9301 15.62 83.72 ..1
9193 15.44 99.15 .11
207 0.35 99.50 11.
193 0.32 99.82 1.1
63 0.11 99.93 1..
43 0.07 100.00 .1.

59558 100.00 XXX

Many thanks in anticipation.

[Nick Cox]

What you want is not clear to me.

You have many panels (people) observed in waves 345, some observed in 34 only, some observed in 45 only, and so on. Do you want to restrict analyses only to incomplete panels, say 34 and 45?

[Charles Ackah]

Nick Cox, Thanks for the feedback, and sorry for the confusion. What I am trying to do is create a panel of individuals observed for at least 2 consecutive waves., i.e 34, 345, or 45. Thanks very much.

[Nick Cox]

There is a risk here of confusion over terminology.

As I understand it, a panel is an individual (person, firm, whatever) observed over time. A panel dataset typically consists of several panels observed over time. You want a smaller panel dataset.

Here is one way to subdivide. The principle and the technique should be clear, but if more detail is needed, check out https://journals.sagepub.com/doi/pdf...36867X20909698

* Example generated by -dataex-. To install: ssc    install    dataex
clear
input float hhid long pid float(wave pcy)
300000 304623 3  7.468816
300000 304624 3  7.468816
300000 304623 4  8.191607
300000 304623 5  8.257506
300000 304624 4  8.191607
300000 304624 5  8.257506
300001 305268 5  7.597524
300001 305269 4    9.4975
300001 620952 3 8.5963335
300001 305268 3 8.5963335
300001 305268 4  7.684784
300001 620952 4  7.684784
300001 305269 5  9.610334
300001 305250 5  7.597524
300001 305250 4  7.684784
300001 305269 3 8.5963335
300001 305249 5  7.597524
300001 305249 3 8.5963335
300001 305250 3 8.5963335
300001 620952 5  7.597524
300001 305249 4  7.684784
300002 319161 4  6.932395
300002 319161 5  7.663094
300002 319161 3  6.956741
300003 402779 4  6.825533
300003 309522 3         .
300003 305291 4  7.828432
300003 583034 5  8.317959
300003 402779 5  6.854149
300003 305291 3         .
300003 582536 5  6.854149
300003 309522 5         .
300003 305291 5  6.854149
300003 583034 3         .
300003 582536 4  7.828432
300003 582536 3         .
300003 309522 4         .
300003 583034 4  7.835113
300003 402779 3         .
300004 302034 5  9.338085
300004 302034 3 9.2136755
300004 302034 4  9.330969
300005 303039 4  7.448096
300005 303039 5  6.725547
300005 303039 3  9.211509
300006 305649 3  7.071443
300006 311353 4    7.9242
300006 311353 5         .
300006 311353 3  7.071443
300006 305649 5   7.90295
300006 305649 4  7.922594
300007 407393 4         .
300007 407393 3         .
300007 407397 3         .
300007 407397 5  6.300319
300007 407397 4         .
300007 407393 5  7.196711
300008 410590 5  6.955804
300008 321630 5  6.955804
300008 321630 4   6.84182
300008 410590 4   6.84182
300008 319052 4   6.84182
300008 319052 5  7.327477
300008 321631 3  7.437262
300008 319052 3  7.437262
300008 321631 5  6.955804
300008 410590 3  7.437262
300008 321631 4   6.84182
300008 321630 3  7.437262
300009 301903 5  9.647812
300009 301903 3  8.786242
300009 301903 4 10.103908
300010 409493 4  7.346483
300010 620604 3         .
300010 409494 5  7.333076
300010 381188 5  6.345164
300010 381188 3         .
300010 409494 3         .
300010 409493 5  7.333076
300010 409493 3         .
300010 620604 4   7.47222
300010 381188 4   7.47222
300010 620604 5   7.30386
300010 409494 4  7.346483
300011 470329 3         .
300011 319825 3         .
300011 319824 3         .
300011 470329 5         .
300011 319823 5         .
300011 319823 3         .
300011 319825 5         .
300011 319823 4         .
300011 319825 4         .
300011 470329 4         .
300011 319824 4         .
300011 319824 5         .
300012 720804 4   7.06202
300012 315004 3  6.578661
300012 720802 3  6.578661
300012 408582 3  6.578661
300012 407674 4  7.120476
300012 315004 5  5.729524
300012 315006 5         .
300012 720803 4   7.06202
300012 720805 3  6.578661
300012 408583 5  6.731416
300012 408582 5  6.731416
300012 315004 4   7.06202
300012 720804 3  6.578661
300012 720802 5  5.729524
300012 720804 5         .
300012 315005 4   7.06202
300012 720805 5  5.729524
300012 720802 4   7.06202
300012 408583 3  6.578661
300012 720805 4   7.06202
300012 407674 5  6.731416
300012 315005 5  5.729524
300012 720803 3  6.578661
300012 315005 3  6.578661
300012 408583 4  7.120476
300012 407674 3  6.578661
300012 408582 4  7.120476
300012 315006 3         .
300012 720803 5  5.729524
300012 315006 4         .
300013 317604 4  5.165946
300013 406032 5  6.362245
300013 406047 4  5.165946
300013 406032 4  5.165946
300013 317604 5  6.362245
300013 406032 3  7.121995
300013 406047 5  6.362245
300013 406047 3  7.121995
300013 317604 3  7.121995
300014 722781 5         .
300014 722782 5  8.229511
300014 315641 5  7.850154
300014 408664 4  7.921302
300014 722781 4         .
300014 408615 5  8.229511
300014 722782 4  7.921302
300014 315604 4         .
300014 722781 3         .
300014 408664 3  7.744731
300014 408615 3  7.744731
300014 315605 3         .
300014 408605 4  7.921302
300014 315604 5         .
300014 315641 3  7.744731
300014 315605 4         .
300014 315637 4  7.921302
300014 408605 3  7.744731
300014 315641 4  7.921302
300014 315605 5         .
300014 408605 5  7.850154
300014 408664 5  7.850154
300014 722782 3  7.744731
300014 315637 3  7.744731
300014 408615 4  7.921302
300014 315604 3  7.744731
300014 315637 5  7.850154
300015 304188 3  7.834811
300015 304185 3  7.834811
300015 730216 5         .
300015 405518 4   6.88641
300015 730216 3  7.834811
300015 304185 5  7.958376
300015 304187 4         .
300015 405518 5  7.958376
300015 730216 4         .
300015 304187 5         .
300015 405518 3  7.834811
300015 304185 4   6.88641
300015 304187 3         .
300015 304188 5  7.958376
300015 304188 4   6.88641
300016 630586 5  5.179518
300016 409643 3  5.737711
300016 409643 4  6.624718
300016 409642 5  7.942819
300016 316342 4  6.624718
300016 409642 3  5.737711
300016 316343 3  5.737711
300016 316343 5  5.179518
300016 630586 4  6.624718
300016 316342 5  5.179518
300016 409641 3  5.737711
300016 316341 4  6.624718
300016 316343 4  6.624718
300016 316342 3  5.737711
300016 409643 5  5.179518
300016 316341 3  5.737711
300016 409641 4  6.624718
300016 409642 4   7.42242
300016 630586 3  5.737711
300016 316341 5  6.985971
300016 409641 5  5.179518
300017 306543 4  6.571434
300017 403621 3   6.13646
end
label var pid "Person identifier" 
label var pcy "log per capita household income"

bysort pid (wave) : gen pattern = string(wave) if _n == 1 
by pid : replace pattern = pattern[_n-1] + string(wave) if _n > 1 
by pid : replace pattern = pattern[_N]

tabdisp pid if !inlist(pattern, "34", "45", "345"), c(pattern)

tabdisp pid if inlist(pattern, "34", "45", "345"), c(pattern)

 
. tabdisp pid if !inlist(pattern, "34", "45", "345"), c(pattern)

----------------------
Person    |
identifie |
r         |    pattern
----------+-----------
   306543 |          4
   403621 |          3
----------------------

. 
. tabdisp pid if inlist(pattern, "34", "45", "345"), c(pattern)

----------------------
Person    |
identifie |
r         |    pattern
----------+-----------
   301903 |        345
   302034 |        345
   303039 |        345
   304185 |        345
   304187 |        345
   304188 |        345
   304623 |        345
   304624 |        345
   305249 |        345
   305250 |        345
   305268 |        345
   305269 |        345
   305291 |        345
   305649 |        345
   309522 |        345
   311353 |        345
   315004 |        345
   315005 |        345
   315006 |        345
   315604 |        345
   315605 |        345
   315637 |        345
   315641 |        345
   316341 |        345
   316342 |        345
   316343 |        345
   317604 |        345
   319052 |        345
   319161 |        345
   319823 |        345
   319824 |        345
   319825 |        345
   321630 |        345
   321631 |        345
   381188 |        345
   402779 |        345
   405518 |        345
   406032 |        345
   406047 |        345
   407393 |        345
   407397 |        345
   407674 |        345
   408582 |        345
   408583 |        345
   408605 |        345
   408615 |        345
   408664 |        345
   409493 |        345
   409494 |        345
   409641 |        345
   409642 |        345
   409643 |        345
   410590 |        345
   470329 |        345
   582536 |        345
   583034 |        345
   620604 |        345
   620952 |        345
   630586 |        345
   720802 |        345
   720803 |        345
   720804 |        345
   720805 |        345
   722781 |        345
   722782 |        345
   730216 |        345
----------------------