Hi all

I am currently calculating herd behavior on the trading platform "Robinhood" and I am using the herd measure proposed by Lakonishok et al. (1992):

The herding measure is given by H(i) = |B(i)/(B(i) + S(i)) - p(t)| - AF(i)

Array
But I am having trouble estimating the AF(i) meassurement, as I understand it is a bernoulli distribution but how is that done in stata? I have searched FAQ and help in stata but I cannot locate how to do this.

Below is an example of my data:

Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input double date str8 TICKER str4 sic float users double(outstanding trade adj price) float(diff_users b s p)
21306 "A" "3826"  590 322477000  2061403 1 65.91   0   0   0   0
21307 "A" "3826"  587 322477000  2225841 1 66.34  -4   1   5   6
21308 "A" "3826"  588 322477000  1331017 1    67   1   1   0   1
21311 "A" "3826"  586 322477000  1424232 1 67.39  -2   0   2   2
21312 "A" "3826"  577 322477000  1668093 1 67.37  -9   5  14  19
21313 "A" "3826"  581 322477000  2107489 1 68.13   4   5   1   6
21314 "A" "3826"  583 322477000  1825105 1 68.86   2   2   0   2
21315 "A" "3826"  596 322477000  1523673 1 69.45  13  16   3  19
21318 "A" "3826"  662 322477000  3297035 1 69.21  66  88  22 110
21319 "A" "3826"  910 322477000 14450240 1  62.5 248 360 112 472
21320 "A" "3826" 1187 322477000  5636249 1 61.94 276 328  52 380
21321 "A" "3826" 1225 322477000  5211171 1 63.59  39  57  18  75
21322 "A" "3826" 1147 322477000  4163534 1 64.32 -79  32 111 143
21325 "A" "3826" 1083 322477000  4287339 1 65.55 -64  17  81  98
21326 "A" "3826" 1001 322477000  3415567 1 64.84 -81  48 129 177
21327 "A" "3826"  940 322477000  3222445 1 64.53 -62  17  79  96
21328 "A" "3826"  922 322477000  1525770 1 64.12 -18   2  20  22
21329 "A" "3826"  906 322477000  1742002 1 63.15 -16   8  24  32
21333 "A" "3826"  904 322477000  3558198 1 61.85  -2   1   3   4
21334 "A" "3826"  910 322477000  1731382 1 62.69   6   8   2  10
21335 "A" "3826"  906 322477000  2465067 1 61.92  -4   3   7  10
21336 "A" "3826"  895 319952000  2200075 1 62.78 -11   3  14  17
21339 "A" "3826"  883 319952000  1957437 1 63.38 -13   1  14  15
21340 "A" "3826"  875 319952000  1889410 1 63.52  -7   2   9  11
21341 "A" "3826"  862 319952000  3177630 1 65.19 -13   9  22  31
21342 "A" "3826"  828 319952000  2955175 1 65.23 -34  17  51  68
21343 "A" "3826"  813 319952000  3639261 1 65.73 -15   1  16  17
21346 "A" "3826"  797 319952000  2922538 1 66.13 -17   9  26  35
21347 "A" "3826"  780 319952000  2001230 1 66.32 -17   6  23  29
21348 "A" "3826"  776 319952000  3559516 1 66.26  -4   2   6   8
21349 "A" "3826"  768 319952000  3458414 1 66.31  -8   5  13  18
21350 "A" "3826"  758 319952000  4113230 1 66.13 -10   1  11  12
21353 "A" "3826"  751 319952000  2563129 1 64.97  -8   3  11  14
21354 "A" "3826"  751 319952000  4615586 1 63.52   0   0   0   0
21355 "A" "3826"  753 319952000  4941764 1 62.79   2   3   1   4
21356 "A" "3826"  752 319952000  4035457 1 63.04   0   0   0   0
21357 "A" "3826"  747 319952000  3259875 1 62.79  -5   1   6   7
21360 "A" "3826"  742 319952000  2417981 1  61.2  -5   3   8  11
21361 "A" "3826"  739 319952000  3628129 1 61.98  -3   2   5   7
21362 "A" "3826"  739 319952000  2025823 1 61.14   0   0   0   0
21363 "A" "3826"  765 319952000  1564067 1 61.29  26  38  12  50
21364 "A" "3826"  818 319952000  1913844 1 61.84  52  63  11  74
21367 "A" "3826"  838 319952000  1526468 1 61.47  21  31  10  41
21368 "A" "3826"  841 319952000   864379 1 61.25   3   4   1   5
21370 "A" "3826"  834 319952000  2247532 1  61.8  -6   3   9  12
21371 "A" "3826"  827 319952000  2269660 1 62.29  -8   5  13  18
21374 "A" "3826"  819 319952000  1504576 1 63.12  -8   4  12  16
21375 "A" "3826"  811 319952000  1922950 1 63.67  -8   1   9  10
21376 "A" "3826"  808 319952000  1779797 1 62.86  -4   2   6   8
21377 "A" "3826"  801 319952000  1748125 1 63.45  -7   0   7   7
21378 "A" "3826"  791 319952000   963652 1 63.38  -9   5  14  19
21381 "A" "3826"  791 319952000   929264 1 62.72   0   0   0   0
21382 "A" "3826"  786 319952000  1469490 1 63.04  -5   3   8  11
21383 "A" "3826"  777 319952000  1201916 1 62.99  -9   4  13  17
21384 "A" "3826"  770 319952000  1726698 1 64.15  -7   2   9  11
21385 "A" "3826"  761 319952000  1619850 1 63.85  -9   1  10  11
21388 "A" "3826"  757 319952000  1413868 1 63.72  -4   2   6   8
21389 "A" "3826"  752 319952000  2454378 1 64.79  -5   1   6   7
21390 "A" "3826"  742 319952000  2925788 1 65.96 -11   2  13  15
21391 "A" "3826"  733 319952000  2583376 1 66.75  -9   4  13  17
21392 "A" "3826"  725 319952000  2638902 1 65.75  -8   4  12  16
21395 "A" "3826"  720 319952000  1588719 1 64.63  -6   4  10  14
21396 "A" "3826"  713 319952000  2537170 1 66.04  -7   3  10  13
21397 "A" "3826"  712 319952000  2679180 1 64.98   0   0   0   0
21398 "A" "3826"  713 319952000  2263190 1 65.29   1   1   0   1
21399 "A" "3826"  715 319952000  1857308 1 65.73   2   2   0   2
21402 "A" "3826"  714 319952000  2873080 1 66.51  -1   0   1   1
21403 "A" "3826"  707 319952000  2829039 1 67.66  -7   1   8   9
21404 "A" "3826"  700 319952000  1681850 1 67.38  -7   3  10  13
21406 "A" "3826"  724 319952000  2165669 1 66.26  24  29   5  34
21409 "A" "3826"  761 319952000  2983080 1 65.94  37  54  17  71
21410 "A" "3826"  794 319952000  3104939 1 66.75  34  45  11  56
21411 "A" "3826"  844 319952000  6071456 1 64.73  50  58   8  66
21412 "A" "3826"  790 319952000  3149457 1  65.5 -54  16  70  86
21413 "A" "3826"  766 319952000  2449200 1 64.66 -24   0  24  24
21416 "A" "3826"  755 319952000  1616049 1 64.47 -11   5  16  21
21417 "A" "3826"  752 319952000  2982592 1 64.93  -2   0   2   2
21418 "A" "3826"  743 319952000  2565558 1 65.65  -9   1  10  11
21419 "A" "3826"  732 319952000  2284920 1 65.69 -11   1  12  13
21420 "A" "3826"  720 319952000  1904191 1 65.98 -13   2  15  17
21423 "A" "3826"  715 319952000  1158772 1 66.08  -5   1   6   7
21424 "A" "3826"  713 319952000  2284317 1 66.69  -1   0   1   1
21425 "A" "3826"  709 319952000  1849586 1 67.01  -5   0   5   5
21426 "A" "3826"  708 319952000  2246300 1 67.26   0   0   0   0
21427 "A" "3826"  707 318770000  1564248 1 67.54  -2   0   2   2
21431 "A" "3826"  699 318770000  1725279 1 67.27  -7   2   9  11
21432 "A" "3826"  696 318770000  1859604 1 66.96  -3   0   3   3
21433 "A" "3826"  691 318770000  1025754 1 67.36  -4   1   5   6
21434 "A" "3826"  691 318770000  1585323 1  67.4   0   0   0   0
21437 "A" "3826"  691 318770000  2065570 1 67.93   0   0   0   0
21438 "A" "3826"  692 318770000  1676678 1 67.62   1   1   0   1
21439 "A" "3826"  688 318770000  1121733 1 67.91  -4   3   7  10
21440 "A" "3826"  683 318770000  2489811 1 69.33  -5   3   8  11
21441 "A" "3826"  679 318770000  1442990 1 68.85  -5   3   8  11
21444 "A" "3826"  683 318770000  1816610 1 69.08   4   5   1   6
21445 "A" "3826"  689 318770000  1780417 1 68.93   7  10   3  13
21446 "A" "3826"  688 318770000  1183392 1 69.56  -1   0   1   1
21447 "A" "3826"  688 318770000  2865626 1 71.13   0   0   0   0
21448 "A" "3826"  687 318770000  3118266 1 70.72  -1   0   1   1
21451 "A" "3826"  689 318770000  2330150 1 69.95   2   3   1   4
end
format %td date
------------------ copy up to and including the previous line ------------------

Listed 100 out of 466334 observations
Use the count() option to list more

Thank you very much in advance!

Best regards

Mathias Sorensen