Hi everyone,

I have 2 years datasets (2007 and 2009) which has information on household food borrowing networks. In 2007 and 2009, households were asked to report up to 3 household ids from which they borrow food from. My dataset is in the wide-format and food_borrow_netid1-food_borrow_netid3 are the three network ids the household reports borrowing food from.

I want to create a variable broken_link with the following rules:

1) takes the value of 1 if food_borrow_netid is mentioned in 2007 (any of the three mentioned ids) but not in 2009 (any of the 3 mentioned ids)
2) takes the value of 0 if the food_borrow_netid is mentioned in both 2007 and 2009
3) It will also be interesting to have a variable that counts the total number of links maintained.

Any help in this regard will be highly appreciated

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input byte branchid int(spotno hhno year food_borrow_netid1 food_borrow_netid2 food_borrow_netid3)
1 1  46 2007  45   .   .
1 1  46 2009 205  44  45
1 1  57 2007  56   .   .
1 1  57 2009 202  93  47
1 1  85 2007  77  76  78
1 1  85 2009  86  21  90
1 1  86 2007  77   .   .
1 1  86 2009  16  77  87
1 1  87 2007  77   .   .
1 2   6 2007   4   .   .
1 2   6 2009   1   5   4
1 2  26 2007  23  24  25
1 2  26 2009  23  24  25
1 2  30 2007  31   .   .
1 2  30 2009  30  31  36
1 2  36 2007  39   .   .
1 2  36 2009  36  37  39
1 2  39 2007  38   .   .
1 2  39 2009  38  40  37
1 2  54 2007 210 211   .
1 2  54 2009  50  55  56
1 2  80 2007  60   .   .
1 2  80 2009  60  81  83
1 3   6 2009  10  11  13
1 3   9 2009   7  11  12
1 3  16 2009  14  15  13
1 3  17 2009  15  14  13
1 3  27 2009  21  24  20
1 3  41 2007  36  49  50
1 3  41 2009  36  49  40
1 3  46 2007  49  50  63
1 3  46 2009  49  50  63
1 3  47 2007  48  49  50
1 3  47 2009  48  49  50
1 3  51 2007  53  56  60
1 3  51 2009  53  65  60
1 3  52 2009  49  50  53
1 3  78 2009  77  82  81
1 3  98 2007 101 102 104
1 3  98 2009  93  94   2
1 4   2 2007   6   .   .
1 4  12 2007  13  14  15
1 4  17 2007  12   .   .
1 4  17 2009  14  15  16
1 4  33 2007  28  24  30
1 4  33 2009  37  32  30
1 4  34 2007  35  36   .
1 4  34 2009  35  36  31
1 4  44 2007  43   .  45
1 4  44 2009  43  46  45
1 4  46 2007  43  44  45
1 4  46 2009  46  45  44
1 4  51 2007  53  54  55
1 4  51 2009  53  54  55
1 4  56 2007  57  58   .
1 4  56 2009  54  55  57
1 4  64 2007  60   .   .
1 4  71 2007  74   .   .
1 4  71 2009  20  69  67
1 4  78 2007  77  74   .
1 4  78 2009  77  79  81
1 4  83 2007  82  77  78
1 4  83 2009  82  77  78
1 4  86 2007 118   .   .
1 4  86 2009 118  90  89
1 4  90 2007  88   .   .
1 4  90 2009  89  88  91
1 4 110 2009  73 111 112
1 4 120 2007 116 117   .
1 4 120 2009 116 112 111
1 4 130 2007 128   .   .
1 4 130 2009 128 126 127
1 4 131 2007 134 135   .
1 4 131 2009 136 139 138
1 5  16 2009  17  18  28
1 5  24 2009  25  26  27
1 5  32 2007  28  29   .
1 5  32 2009  31  33  34
1 5  35 2007  36  38   .
1 5  35 2009  37  38  34
1 5  56 2009  57  58  67
1 5  76 2009  75  77  78
1 6   1 2009   5   7  15
1 6   2 2009   5   3   4
1 6   6 2009   4   7  15
1 6   9 2007  10  28   8
1 6  17 2009  15  16  18
1 6  36 2009  35  37  39
1 6  38 2009  36  37  39
1 6  47 2009  46  45  50
1 6  48 2009 202 203  47
1 6  52 2009  53  54  50
1 6  54 2009  57  61  62
1 6  61 2009  60  56  62
1 6  90 2009  88  86  85
1 7   6 2009  15  16  14
1 7  16 2009  15  17  18
1 7  27 2007  26   .   .
1 7  27 2009  26  28  29
1 7  36 2007  34  35   .
end