Dear Statalisters,

I am running into an issue with rolling windows and I need your kind help with this.
I want to run a loading-estimation regression for each portfolio of the 25 portfolios:
∑_(j=1)^3▒〖r_i,t+j=β_0+β_rm ∑_(j=1)^3▒〖r_m ,_(t+j)+β_vs (VS_(t+3)-VS_t )+β_TY (TY_(t+3)-TY_t )+ε_i,t+3〗〗
where r_i is the log return for portfolio i for month t. the regression is reestimated from a rolling 36-month window of overlapping observations for each portfolio
here is my dataset :
----------------------- copy starting from the next line -----------------------
Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input int mdate str7 portfolio long Date double(R_Me TY PE VS EtR_Me N_dr N_cf Rrf return) int year float(beta_cf beta_dr beta)
-372 "FFS1BM1" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0294 1929     .05924752  .3262584  .3855059
-372 "FFS1BM2" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0725 1929    -.06193411  .4790082 .41707405
-372 "FFS1BM3" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0359 1929     .00982766  .4029027  .4127304
-372 "FFS1BM4" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0342 1929   -.005368913  .5225681  .5171992
-372 "FFS1BM5" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356         .045 1929   -.019985776  .5527377  .5327519
-372 "FFS2BM1" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0263 1929   .0032415094  .6284044  .6316459
-372 "FFS2BM2" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0154 1929   -.020822156  .5552655  .5344433
-372 "FFS2BM3" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0048 1929   .0042878776  .4580335  .4623214
-372 "FFS2BM4" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356       -.0119 1929      .0352345  .3948077  .4300422
-372 "FFS2BM5" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356       -.0098 1929 -.00009482048  .5912477 .59115285
-372 "FFS3BM1" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0085 1929    .011321996  .6915067  .7028287
-372 "FFS3BM2" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356         .061 1929    .001216485  .5897798 .59099627
-372 "FFS3BM3" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356       -.0185 1929    .009671984 .29456446  .3042364
-372 "FFS3BM4" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0347 1929   -.011182434  .5506634   .539481
-372 "FFS3BM5" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0294 1929     .01597782 .55004495 .56602275
-372 "FFS4BM1" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0387 1929     .02939587  .7167775  .7461734
-372 "FFS4BM2" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0368 1929   -.012668965 .55318886  .5405199
-372 "FFS4BM3" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0458 1929    .015964294  .4676221  .4835864
-372 "FFS4BM4" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356       -.0053 1929   -.007218322  .4046834 .39746505
-372 "FFS4BM5" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0429 1929     .03732603  .5744621  .6117882
-372 "FFS5BM1" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0578 1929    .036220156  .6428615  .6790817
-372 "FFS5BM2" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0972 1929    .010005615  .7341053  .7441109
-372 "FFS5BM3" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0298 1929    .008297929  .5592648  .5675627
-372 "FFS5BM4" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356        .0526 1929    .003646429   .440443  .4440894
-372 "FFS5BM5" 192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356       -.0064 1929   .0008559166  .3263886  .3272445
-372 "RISK1"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .098431561 1929    .028652295  .7569353  .7855876
-372 "RISK10"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356  .0061030286 1929    .062652744   .727827  .7904797
-372 "RISK11"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .098908375 1929     .02620109  .6222121  .6484131
-372 "RISK12"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .062109543 1929    -.03625267   .666667  .6304144
-372 "RISK13"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .093045235 1929    .013913565  .6706531  .6845667
-372 "RISK14"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356    .03877791 1929    .014974905   .745456  .7604309
-372 "RISK15"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   -.01948815 1929     .05293516  .7823805  .8353156
-372 "RISK16"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356    .04721912 1929      .0355169  .5424857 .57800263
-372 "RISK17"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .040854409 1929   -.004129561  .3801437  .3760142
-372 "RISK18"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356  .0034716927 1929    .024188194  .4141795  .4383677
-372 "RISK19"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356    .06832487 1929 -.00048961496 .56538683 .56489724
-372 "RISK2"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .053369589 1929     -.0224927  .4826655  .4601728
-372 "RISK20"  192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356    .15243614 1929     .04937126  .7318066  .7811779
-372 "RISK3"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .032101969 1929    .006431182  .4661315  .4725627
-372 "RISK4"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .088620282 1929    .028872114  .6427931  .6716652
-372 "RISK5"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356    .11580332 1929    .033250034  .8001252  .8333753
-372 "RISK6"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .041898925 1929    .034086682 .37238285  .4064695
-372 "RISK7"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356  .0062128445 1929    .003068335 .52689254  .5299609
-372 "RISK8"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .087512204 1929     .02363682 .58461994  .6082568
-372 "RISK9"   192901 .047326726 -.75 3.2885226 1.8517692  -.011840795 .093003782 -.033836261 .004583356   .061116683 1929    -.00983582  .7372195  .7273837
-360 "FFS1BM1" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247       -.0276 1930      .8514435 1.4963475 2.3477912
-360 "FFS1BM2" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247         .179 1930      .3367208 1.5055708 1.8422916
-360 "FFS1BM3" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .2242 1930     .05446751  1.562088 1.6165555
-360 "FFS1BM4" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .1107 1930     .28239095  .9522714 1.2346623
-360 "FFS1BM5" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .1209 1930     .25897858  1.315512 1.5744907
-360 "FFS2BM1" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .1055 1930     .07765845  1.057515 1.1351734
-360 "FFS2BM2" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0759 1930     .22215386 1.0263426 1.2484965
-360 "FFS2BM3" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0733 1930     .17719717  .9164881 1.0936853
-360 "FFS2BM4" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0713 1930      .2434063  1.102811 1.3462173
-360 "FFS2BM5" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .1341 1930      .3220559 1.3403084 1.6623644
-360 "FFS3BM1" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0827 1930      .2048683  .9816515 1.1865199
-360 "FFS3BM2" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .1103 1930      .3170917 1.1434426 1.4605343
-360 "FFS3BM3" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0568 1930     .17558993  .9498575 1.1254474
-360 "FFS3BM4" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0634 1930     .24670826 1.2003797  1.447088
-360 "FFS3BM5" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0235 1930      .3086642  1.372513  1.681177
-360 "FFS4BM1" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0973 1930     .23327154 1.1514522 1.3847237
-360 "FFS4BM2" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0735 1930     .22635753  .9152788 1.1416364
-360 "FFS4BM3" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0578 1930     .13564633  .8470545  .9827009
-360 "FFS4BM4" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0392 1930     .22174554  .9943134  1.216059
-360 "FFS4BM5" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0352 1930      .3222606 1.2576398 1.5799004
-360 "FFS5BM1" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0675 1930     .21648957 1.0605837 1.2770733
-360 "FFS5BM2" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0582 1930     .17482665  .9223513  1.097178
-360 "FFS5BM3" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0144 1930     .12300026    .95253 1.0755303
-360 "FFS5BM4" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247        .0457 1930     .08322594   .842245  .9254709
-360 "FFS5BM5" 193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247       -.0093 1930      .0595389  .7976518  .8571907
-360 "RISK1"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247 -.0017166322 1930     .14502192  .8435753  .9885972
-360 "RISK10"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .099690376 1930      .2652537 1.4115243  1.676778
-360 "RISK11"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .054981765 1930     .17238738   .856903 1.0292904
-360 "RISK12"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .058936974 1930      .2021969  .9037679 1.1059649
-360 "RISK13"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .037711523 1930     .19930057  .8474494   1.04675
-360 "RISK14"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .093524578 1930     .27839682 1.1880533   1.46645
-360 "RISK15"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .088494497 1930       .381925 1.6126454 1.9945704
-360 "RISK16"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .010481391 1930     .08959346  .7620437  .8516371
-360 "RISK17"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .019530484 1930    .063040785  .7007203  .7637611
-360 "RISK18"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .040227866 1930     .15270185  .7582238  .9109257
-360 "RISK19"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .069703499 1930       .211524 1.0842286 1.2957526
-360 "RISK2"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .038348348 1930      .0975077  .8845042  .9820119
-360 "RISK20"  193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .092581748 1930      .3060017 1.4533845 1.7593862
-360 "RISK3"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .039177107 1930     .29500562  .9773009 1.2723064
-360 "RISK4"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .053244606 1930      .2137086 1.1145675  1.328276
-360 "RISK5"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247    .08175016 1930      .3345693 1.5580887  1.892658
-360 "RISK6"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .057623705 1930     .13980031  .5836796  .7234799
-360 "RISK7"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .031550058 1930     .03155405  .6354066  .6669606
-360 "RISK8"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247   .054729526 1930      .2091765  .7284901  .9376665
-360 "RISK9"   193001 .050306074 -.21 3.1068586 1.7823571 -.0045525239 .033381586  .021477012 .004067247     .0782001 1930      .2264739 1.1742008 1.4006747
-348 "FFS1BM1" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752       -.2396 1931     .53487426  1.496919 2.0317934
-348 "FFS1BM2" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752         .278 1931      .4120084 1.8344772 2.2464857
-348 "FFS1BM3" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752       -.0638 1931     .51941764  2.202763  2.722181
-348 "FFS1BM4" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752        .1587 1931     .53789824 2.0833216   2.62122
-348 "FFS1BM5" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752         .207 1931      .6080906 2.3335495   2.94164
-348 "FFS2BM1" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752        .0913 1931      .3761408  1.270577 1.6467175
-348 "FFS2BM2" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752        .1287 1931      .3867088 1.3341855 1.7208943
-348 "FFS2BM3" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752        .0856 1931      .3951588 1.5664396 1.9615984
-348 "FFS2BM4" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752        .1513 1931     .49635255 1.8770934  2.373446
-348 "FFS2BM5" 193101 .058128412  .32 2.7409704 2.1235241  -.010630567 .079554558 -.010795579 .002291752        .1669 1931      .6203617 2.0933096  2.713671
end
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