set more on
clear
input hnr str5 hcity hnkids str1 medu minc90 minc91 str1 fedu finc90 finc91
1 NY   3 B 30000 32000 H 23000 23700 
2 Phil 1 B 31000 33100 B 34200 35200
3 SF   2 M 43000 45100 B 35000 37250
end
li , nodisplay noobs
more

reshape2 id hnr
reshape2 cons hcity hnkids
reshape2 groups sex m f, string
reshape2 vars @inc90 @inc91 @edu
reshape2 long
sort hnr
li, nodisplay noobs
more

reshape2 id hnr sex
reshape2 cons hcity hnkids edu
reshape2 groups year 90-91
reshape2 vars  inc@
reshape2 long
sort hnr sex year
li, nodisplay noobs