Hi statalist, I have a tricky problem in which I have a large set of individuals, with individuals belonging to a group. Each individual has an amount of an item (item A, item B, item C..... item AB, item AC.... item AAA, etc etc).

My job is to sum the amount of items each group has, my data looks like this in long data:


Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input float(group id) str9 firstname str8 lastname str2 item1 float count_1 str2 item2 float count2
1 1 "bob"   "jones"  "A"   20 "B"    1
1 2 "sean"  "smith"  "F"   10 "A"    5
2 1 "peter" "joe"    "OO" 100 "AC"  20
2 2 "lily"  "milner" "AB"  10 "OO" 100
2 3 "yusef" "notib"  "OO"  14 "AB"   4
end

Here is code for wide "reshape wide firstname lastname item* count*, j(id) i(group)"

Code:
     +----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
     | group   firstn~1   lastna~1   item11   count_11   item21   count21   firstn~2   lastna~2   item12   count_12   item22   count22   firstn~3   lastna~3   item13   count_13   item23   count23 |
     |----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
  1. |     1        bob      jones        A         20        B         1       sean      smith        F         10        A         5                                         .                  . |
  2. |     2      peter        joe       OO        100       AC        20       lily     milner       AB         10       OO       100      yusef      notib       OO         14       AB         4 |
     +----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+


My goal is to collapse my data by group, such that group 1 would have the items across individual 1 and 2 summed together... Any advice?