Linking parents with children in Stata

[Nthato Ras]

Dear All,

I'm trying to connect parents attributes like education and BMI to child on Stata 16. My commands are as follows:

by hhid (pid), sort: gen pid1=_n
gen empl_f=.
gen empl_m=.
gen educ_f=.
gen educ_m=.
gen wt_f=.
gen wt_m=.
sum pid1, meanonly
forval i =  1/`r(max)' {

However, when I get to

forval i =  1/`r(max)' {

command, I get an r(612) error message stating the following

unexpected end of file.

Please advise if there is something that I'm missing. I read the meaning of the error message and tried the suggestions of closing the bracket, but this is not correct.

Thanks
Nthato

[Clyde Schechter]

What comes on the subsequent lines of your do-file after -forval i = 1/`r(max)' {-?

If you are running these commands out of a do-file and that is the last command in the do-file, and this is all there is (or this is all that has been selected) then the error message is appropriate: the end of the do-file has been reached at a point where there should be more code following, but instead the end of file is found.

That said, in Stata, when you find yourself writing a loop over observations, as here, you are probably heading down the wrong path. Occasionally this is needed in Stata, but it is very uncommon. And usually when the issue is linking data values between parents and children or other household members, there are ways to do this using linked frames or merging data sets. If you post back showing example data that contains observations on some corresponding parents and children, we could show you better approaches to this. When showing example data, please be sure to use the -dataex- command. If you are running version 17, 16 or a fully updated version 15.1 or 14.2, -dataex- is already part of your official Stata installation. If not, run -ssc install dataex- to get it. Either way, run -help dataex- to read the simple instructions for using it. -dataex- will save you time; it is easier and quicker than typing out tables. It includes complete information about aspects of the data that are often critical to answering your question but cannot be seen from tabular displays or screenshots. It also makes it possible for those who want to help you to create a faithful representation of your example to try out their code, which in turn makes it more likely that their answer will actually work in your data.

[Nthato Ras]

Thank you Clyde.

My dataex results are as follows:

* Example generated by -dataex-. To install: ssc install dataex
clear
input long(hhid pid) float(empl_f empl_m educ_f educ_m wt_f wt_m)
101012 314585 . . . . . .
101013 314544 . . . . . .
101013 314550 . . . . . .
101013 406295 . . . . . .
101013 406297 . . . . . .
101014 314575 . . . . . .
101014 314581 . . . . . .
101014 314582 . . . . . .
101015 314570 . . . . . .
101015 406352 . . . . . .
101016 314110 . . . . . .
101017 314529 . . . . . .
101017 314531 . . . . . .
101020 314543 . . . . . .
101020 406291 . . . . . .
101020 406293 . . . . . .
101020 407218 . . . . . .
101021 314567 . . . . . .
101021 314568 . . . . . .
101021 406324 . . . . . .
101021 406325 . . . . . .
101021 406330 . . . . . .
101022 314558 . . . . . .
101022 314559 . . . . . .
101022 403744 . . . . . .
101022 406326 . . . . . .
101022 406327 . . . . . .
101022 406329 . . . . . .
101023 314523 . . . . . .
101023 314569 . . . . . .
101023 314573 . . . . . .
101023 406331 . . . . . .
101023 406332 . . . . . .
101023 406334 . . . . . .
101023 406335 . . . . . .
101024 314555 . . . . . .
101024 314556 . . . . . .
101024 314572 . . . . . .
101024 406343 . . . . . .
101025 314512 . . . . . .
101025 314517 . . . . . .
101025 314527 . . . . . .
101025 314528 . . . . . .
101025 314586 . . . . . .
101025 314587 . . . . . .
101025 406289 . . . . . .
101025 406345 . . . . . .
101025 406353 . . . . . .
101025 406371 . . . . . .
101025 406372 . . . . . .
101028 313832 . . . . . .
101028 313837 . . . . . .
101028 314553 . . . . . .
101028 314564 . . . . . .
101028 314565 . . . . . .
101028 314566 . . . . . .
101028 406306 . . . . . .
101028 406361 . . . . . .
101028 406362 . . . . . .
101028 406363 . . . . . .
101028 406364 . . . . . .
101028 406365 . . . . . .
101028 407235 . . . . . .
101028 410018 . . . . . .
101029 314557 . . . . . .
101029 406339 . . . . . .
101029 406340 . . . . . .
101030 314505 . . . . . .
101030 406342 . . . . . .
101030 406348 . . . . . .
101030 407203 . . . . . .
101033 314157 . . . . . .
101033 314158 . . . . . .
101033 406344 . . . . . .
101034 314174 . . . . . .
101034 314186 . . . . . .
101034 314521 . . . . . .
101034 314522 . . . . . .
101034 407257 . . . . . .
101034 407258 . . . . . .
101034 407259 . . . . . .
101036 314133 . . . . . .
101036 314134 . . . . . .
101036 314135 . . . . . .
101036 407219 . . . . . .
101036 407220 . . . . . .
101036 407221 . . . . . .
101036 407223 . . . . . .
101037 314131 . . . . . .
101037 314137 . . . . . .
101037 314138 . . . . . .
101037 314141 . . . . . .
101037 407222 . . . . . .
101037 407225 . . . . . .
101037 407239 . . . . . .
101037 407240 . . . . . .
101037 407241 . . . . . .
101037 407248 . . . . . .
101038 314122 . . . . . .
101038 407255 . . . . . .
end

Regards
Nthato

[Nthato Ras]

The commands that should follow are s follows:

by hhid: replace empl_f=employ_stat[`i'] if fthpid==pid[`i'] & !missing(best_fthpid)
by hhid: replace empl_m=empl_stat[`i'] if  mthpid==pid[`i'] & !missing(best_mthpid)

by hhid: replace educ_f=education[`i'] if fthpid==pid[`i'] & !missing(best_fthpid)
by hhid: replace educ_m=education[`i'] if  mthpid==pid[`i'] & !missing(best_mthpid)

by hhid: replace wt_f=bmi[`i'] if fthpid==pid[`i'] & !missing(best_fthpid)
by hhid: replace wt_m=bmi[`i'] if  mthpid==pid[`i'] & !missing(best_mthpid)

[Clyde Schechter]

Thank you for responding. But the problem cannot be solved with the data example you provided. In that example data set, there is no way to know who, within a household, is the father and who is the mother. From the commands you show in #4 (which, by the way, will not give correct results in any case) it appears that the full data set actually contains variables fthpid and mthpid that provide this information. Please post a new data example that contains those variables (or other variables that designate who is the father and who is the mother of whom.) Also, for the data example to be usable, it has to include the variables empl_stat, educ, and bmi.

[Nthato Ras]

Hi Nick,

fthpid and mthpid are given in the data set. I just need to connect mothers education, employment status and BMI to child.

So to include all variables I said

by hhid (pid) fthpid mthpid empl_stat education bmi , sort: gen pid2=_n

The dataex results are

* Example generated by -dataex-. To install: ssc install dataex
clear
input long(hhid pid fthpid mthpid) byte(empl_stat education) float bmi
101012 314585      .      . 0 25  30.86253
101013 314544      .      . 0 25 19.287205
101013 314550      .      . 0 25 23.121824
101013 406295 314544 314550 .  2         .
101013 406297 314544 314550 .  3         .
101014 314575 314582 314580 .  4         .
101014 314581 314582 314580 0  8  25.71166
101014 314582      .      . 0 25 22.857143
101015 314570      .      . 0  5   19.7551
101015 406352      . 314570 .  2         .
101016 314110      .      . 3 25 31.221025
101017 314529      .      . 1 25 19.959356
101017 314531      .      . 1 25 17.892626
101020 314543      .      . 3  4 29.136316
101020 406291      . 314543 . 25         .
101020 406293      . 314543 .  1         .
101020 407218      . 314543 .  1         .
101021 314567      .      . 3  6  27.47957
101021 314568      . 314567 0  9 22.337494
101021 406324      . 314567 .  1         .
101021 406325      . 720007 .  0         .
101021 406330      . 720007 . 25         .
101022 314558      .      . 3 25  19.43852
101022 314559 314558 314560 0  8  23.51697
101022 403744 314558 314560 .  6         .
101022 406326 314558 314560 .  0         .
101022 406327 314558 314560 . 25         .
101022 406329 314558 314560 .  4         .
101023 314523      . 314573 3 25  30.11152
101023 314569      .      . 3 25   24.5632
101023 314573      .      . 0 25 37.109375
101023 406331 314523 314569 .  3         .
101023 406332 314523 314569 .  2         .
101023 406334 314523 314569 . 25         .
101023 406335 314523 314569 . 25         .
101024 314555      .      . 0  6  21.49346
101024 314556      .      . 3  6 20.218273
101024 314572      .      . 1  6  20.99592
101024 406343      .      . .  4         .
101025 314512      .      . 1  6  22.76985
101025 314517      .      . 0 25 33.547276
101025 314527      .      . 3  7 24.609734
101025 314528 314515 314517 0  8  22.67265
101025 314586 314515      . 1  5 18.982437
101025 314587 314515      . 3  3 19.979753
101025 406289      .      . .  1         .
101025 406345 314515 314517 .  3         .
101025 406353      . 314512 .  6         .
101025 406371 314515 314517 .  6         .
101025 406372      .      . .  1         .
101028 313832      .      . 0  8 17.149416
101028 313837      .      . 0 25  23.05878
101028 314553      .      . 3  9  20.90263
101028 314564 776516 788147 0  9 24.012947
101028 314565      . 720013 3  8  20.49311
101028 314566      .      . 0 25  23.73349
101028 406306      . 724583 .  0         .
101028 406361      . 720013 .  6         .
101028 406362      . 720013 .  4         .
101028 406363      .      . .  1         .
101028 406364      . 720013 . 25         .
101028 406365      . 724583 . 25         .
101028 407235      .      . . 25         .
101028 410018 314552 314564 . 25         .
101029 314557 314520 314541 0  7 24.609375
101029 406339 314544      . . 25         .
101029 406340      . 314557 . 25         .
101030 314505      . 314504 0 11 19.693207
101030 406342      . 314505 . 25         .
101030 406348      . 314505 .  8         .
101030 407203      . 314505 .  0         .
101033 314157      . 314158 0  8  20.36029
101033 314158      .      . 0 25 16.527958
101033 406344      . 314119 . 25         .
101034 314174      . 314522 0  6  26.19754
101034 314186      . 314522 0 19      27.6
101034 314521      . 314522 2 12 36.837288
101034 314522      .      . 3  2  33.84577
101034 407257      . 314522 .  4         .
101034 407258 765705 314186 .  0         .
101034 407259      . 314522 .  6         .
101036 314133      . 314135 1 11 30.915577
101036 314134      . 314135 2 12  28.76397
101036 314135      .      . 0  4  32.05128
101036 407219      . 314134 . 25         .
101036 407220      . 314134 .  1         .
101036 407221      . 314133 . 25         .
101036 407223      . 314133 .  0         .
101037 314131 314137 314141 1 10 26.859505
101037 314137      .      . 3  9  25.71101
101037 314138 314137 314141 0  7 21.644444
101037 314141      .      . 0  7   38.7702
101037 407222      . 314131 .  0         .
101037 407225      . 314131 .  0         .
101037 407239 314137 314141 .  3         .
101037 407240 314137 314141 .  6         .
101037 407241 314137 314141 .  3         .
101037 407248 314137 314141 .  0         .
101038 314122      .      . 0  8  26.52501
101038 407255      . 314122 .  3         .
end
label values mthpid w5_id_codes
label values fthpid w5_id_codes
label values empl_stat state_fine_ap
label def state_fine_ap 0 "0. Not Economically Active", modify
label def state_fine_ap 1 "1. Unemployed_Discouraged", modify
label def state_fine_ap 2 "2. Unemployed_Strict", modify
label def state_fine_ap 3 "3. Employed", modify
label values education w5_edgrd
label def w5_edgrd 0 "0. Grade R/0", modify
label def w5_edgrd 1 "1. Grade 1 (Previously Sub A/Class 1)", modify
label def w5_edgrd 2 "2. Grade 2 (Previously Sub B/Class 2)", modify
label def w5_edgrd 3 "3. Grade 3 (Std. 1)", modify
label def w5_edgrd 4 "4. Grade 4 (Std. 2)", modify
label def w5_edgrd 5 "5. Grade 5 (Std. 3)", modify
label def w5_edgrd 6 "6. Grade 6 (Std. 4)", modify
label def w5_edgrd 7 "7. Grade 7 (Std. 5)", modify
label def w5_edgrd 8 "8. Grade 8 (Std. 6/Form 1)", modify
label def w5_edgrd 9 "9. Grade 9 (Std. 7/Form 2)", modify
label def w5_edgrd 10 "10. Grade 10 (Std. 8/Form 3)", modify
label def w5_edgrd 11 "11. Grade 11 (Std. 9/Form 4)", modify
label def w5_edgrd 12 "12. Grade 12 (Std. 10/Matric/Senior Certificate/Form 5)", modify
label def w5_edgrd 19 "19. Diploma requiring Grade 12/Std. 10", modify
label def w5_edgrd 25 "25. No Schooling", modify

[Clyde Schechter]

frame put hhid pid empl_stat education bmi, into(parents)

frame parents: isid hhid pid, sort

frlink m:1 hhid fthpid, frame(parents hhid pid)
foreach v of varlist empl_stat education bmi {
    frget fth_`v' = `v', from(parents)
}

drop parents
frlink m:1 hhid mthpid, frame(parents hhid pid)
foreach v of varlist empl_stat education bmi {
    frget mth_`v' = `v', from(parents)
}
drop parents
frame drop parents

[Nthato Ras]

Hi Nick,

Thanks very much for response #7.

However, I get an error message when I try the 2nd command, [frame parents:isid pid hhid, sort]. The message states

variables pid hhid should never be missing


When I check my data, pids are full, and there's missing numbers in hhid. Could this be the reason or is it something else?

[Clyde Schechter]

[quote]Could this be the reason or is it something else?[/code]
Yes, that would be the reason for it.

Now, when I wrote the code, I assumed that, as in many household surveys, the pid numbers do not identify unique people but can be reused in different households. That is, I assumed that the combination of hhid and pid was required to identify a unique person. If that is not true: if pid alone is enough to completely identify one and only one person, then you can work around this by just removing hhid from the code in every command in that code.

That said, it is very strange indeed to have an observation in a household survey data set where the hhid is missing. This is very likely to represent an error in your data set. So you should investigate how this happened, and fix whatever problems led to it, before proceeding with any further data management or analysis.

By the way, Nick didn't respond on this thread. He and I tend to think alike and often give similar answers (though I am much less succinct in my wording). But we are two different people.

[Nthato Ras]

Thank you so much Clyde. Let me explore this. I will give you an update soon.

Sorry to call you Nick

[Nthato Ras]

Thank you Clyde. The commands were very helpful!