Problem with implementing forward and backward linkages on stata

[Teetee labi]

Hello,

I am currently doing a research on FDI spillovers, at this point i need some help with implementing commands for backward and forward linkages, Here is an example of my data. Please help.


* Example generated by -dataex-. For more info, type help dataex
clear
input str3 iso3 int year double value long industry float(c15t16 c17t19 c20 c21t22 c23 c24 c25 c26 c27 c28 c29 c30t33x)
"USA" 2002 155464878381 1 62525 694.8 50.3 787.9 121.3 2217.7 243.9 79.2 45.4 78.8 76 150.5
"USA" 2002 21477121619 2 393.7 9926.2 238.7 1146.6 66.8 999.3 1017.3 123.3 52.6 95.8 276.6 135.5
"USA" 2002 26484745464 3 230.1 109.2 15096.7 3901.6 11.7 256.6 996.7 338.7 176 214.7 681.8 455.3
"USA" 2002 14077715636 4 16864.1 1854.9 677.9 86218.5 240.2 8907.9 4267.6 1498.4 1086.8 2437.7 2229.2 3580.5
"USA" 2002 1800538900 5 1242.2 351.5 301.2 2079.8 2754.3 8354.8 1017.9 337.3 528.9 728 851 520.3
"USA" 2002 2.7277e+10 6 3313.6 7967.1 1097.7 9100.6 963.9 70272.2 22012.4 2003.1 772.2 3556.4 2108.1 4421.2
"USA" 2002 5.3531e+10 7 9032.3 586.7 475.7 2899.4 116.8 7238.4 9888.4 767.6 398.3 1663.9 4464.3 3401.8
"USA" 2002 1.59209e+11 8 2888.9 369.3 694.1 193.3 445.4 1199.8 961.3 8257.3 852.1 696.3 1001.1 786.3
"USA" 2002 4.4927e+10 9 2621.9 146.6 134.6 469.7 41.2 409.5 893.8 515.9 22050.2 28665.3 12197.1 4290.7
"USA" 2002 1.69567e+11 10 8953.6 984.5 1662.9 6303.5 137.3 5939.8 4136 1668.8 3015.2 18316.8 12891.7 8912.4
"USA" 2002 6.3018e+10 11 1884.4 154.3 467.9 2962.4 133 2635.4 1520 363 1389.4 3279.6 21497.4 1402.4
"USA" 2002 4.1446e+10 12 1627.5 746.8 414.9 4161.6 139.7 2784.2 1180.5 622.2 817.1 2023 3138.9 46427.9
"USA" 2002 4.1352e+10 13 472.1 116.4 213.3 344.1 43 540.6 444 83.9 737.4 1191.1 3792.4 2981
"USA" 2002 1.0521e+11 14 1391.3 181.1 377 1376.7 52.4 895.1 352.9 368.7 311.4 850.5 5121.9 1780.6
"USA" 2002 9.5897e+10 15 269.6 70.3 50.3 392.9 19.9 396.3 116.9 45.6 76 229.9 623.8 402.4
"USA" 2002 22615103901 16 371.8 338.9 473.5 1445.3 55.6 643 399.8 294 3757.5 314.2 983.5 546.7
"USA" 2002 4.2568e+10 17 536970.3 116252.8 85241.3 487096.9 201702.8 427379.1 162922.6 88928.9 131245.2 231087.2 230461.4 336508.8
"USA" 2002 71302132584 18 363627.6 76368.1 59439.6 285213.9 160019.3 267741.9 103244 49734.7 92307.6 131334.6 139634.5 210530.9
"USA" 2002 38655763514 19 -4784.3 471.1 182.9 777.3 1114.9 1895.6 353.6 288.1 455.2 472.5 526.5 313.7
"USA" 2002 1.21309e+11 20 173342.7 39884.7 25801.7 201883 41683.4 159637.3 59678.6 39194.2 38937.5 99752.6 90826.9 125977.9
"USA" 2002 6.7349e+10 21 . . . . . . . . . . . .
"USA" 2002 9.2769e+10 22 . . . . . . . . . . . .
end
label values industry indu
label def indu 1 "C15", modify
label def indu 2 "C16", modify
label def indu 3 "C17", modify
label def indu 4 "C18", modify
label def indu 5 "C19", modify
label def indu 6 "C20", modify
label def indu 7 "C21", modify
label def indu 8 "C22", modify
label def indu 9 "C23", modify
label def indu 10 "C24", modify
label def indu 11 "C25", modify
label def indu 12 "C26", modify
label def indu 13 "C27", modify
label def indu 14 "C28", modify
label def indu 15 "C29", modify
label def indu 16 "C30", modify
label def indu 17 "C31", modify
label def indu 18 "C32", modify
label def indu 19 "C33", modify
label def indu 20 "C34", modify
label def indu 21 "C35", modify
label def indu 22 "C36T37", modify
[/CODE]

[Rich Goldstein]

what are "forward and backward linkages"?

[Teetee labi]

There are variables required when researching on FDI spillovers. I figured out how to create the variables, by simply summing the values of the rows and columns respectively.