Hello,

I have to calculate the cost of equity capital based on fama and french 3 factor model. For this, I had a monthly data from Fama and french website (http://mba.tuck.dartmouth.edu/pages/....html#Research ) . I used rangestat command to calculate the market betas for the 3 factors as below

Code:
rangestat (reg) ret mktrf smb hml, interval(month -60 -1) by(permno)
Then i caculated the monthly expected returns as

Code:
gen ce=rf+mkt+sb+hl+ce
where
mkt, sb, and hl are calculated as

Code:
gen mkt=b_mktrf*mktrf
gen sb=b_smb*smb
gen hl=b_hml*hml
final data file looks like the one below.

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input double(permno date) float month double ret float(year mktrf smb hml rf) double(reg_nobs b_mktrf b_smb b_hml b_cons) float(mkt sb hl ce returns)
10026 11353   1   .01587301678955555 1991   4.69  3.79 -1.84 .52  .                    .                       .                      .                      .           .             .             .         .         0
10026 11381   2                 .375 1991   7.19  3.95  -.54 .48  1                    .                       .                      .                      .           .             .             .         .         0
10026 11409   3   .05681818351149559 1991   2.65  3.89 -1.23 .44  2                    .                       .                      .                      .           .             .             .         .         0
10026 11442   4   .19354838132858276 1991   -.28    .5  1.42 .53  3                    .                       .                      .                      .           .             .             .         .         0
10026 11473   5 -.045045044273138046 1991   3.65  -.34  -.57 .47  4                    .                       .                      .                      .           .             .             .         .         0
10026 11501   6   .07547169923782349 1991  -4.94   .07  1.21 .42  5                    .                       .                      .                      .           .             .             .         .         0
10026 11534   7   .05263157933950424 1991   4.24  -.93 -1.25 .49  6                    .                       .                      .                      .           .             .             .         .         0
10026 11564   8  -.07500000298023224 1991   2.32  1.59  -.78 .46  7                    .                       .                      .                      .           .             .             .         .         0
10026 11595   9                    0 1991  -1.59  1.63    -1 .46  8                    .                       .                      .                      .           .             .             .         .         0
10026 11626  10  -.09909909963607788 1991   1.29    .9  -.43 .42  9                    .                       .                      .                      .           .             .             .         .         0
10026 11655  11  -.03999999910593033 1991  -4.19  -.48 -1.93 .39 10                    .                       .                      .                      .           .             .             .         .         0
10026 11687  12                .1875 1991  10.84 -2.24 -4.03 .38 11                    .                       .                      .                      .           .             .             .         .         0
10026 11718  13   -.2017543911933899 1992   -.59  8.47  4.51 .34 12                    .                       .                      .                      .           .             .             .         .         0
10026 11746  14  -.05494505539536476 1992   1.09   .88  6.37 .28 13                    .                       .                      .                      .           .             .             .         .         0
10026 11778  15   .04651162773370743 1992  -2.66 -1.03  3.65 .34 14                    .                       .                      .                      .           .             .             .         .         0
10026 11808  16                    0 1992   1.07 -6.12  4.31 .32 15                    .                       .                      .                      .           .             .             .         .         0
10026 11837  17                    0 1992     .3   .39  1.28 .28 16                    .                       .                      .                      .           .             .             .         .         0
10026 11869  18  -.15555556118488312 1992  -2.34 -3.09   3.4 .32 17                    .                       .                      .                      .           .             .             .         .         0
10026 11900  19   .02631578966975212 1992   3.77  -.44  -.53 .31 18                    .                       .                      .                      .           .             .             .         .         0
10026 11931  20  .025641025975346565 1992  -2.38  -.12 -1.03 .26 19                    .                       .                      .                      .           .             .             .         .         0
10026 11961  21  -.08749999850988388 1992   1.19   .56  -.21 .26 20                    .                       .                      .                      .           .             .             .         .         0
10026 11991  22 -.054794520139694214 1992   1.02  2.05  -2.1 .23 21                    .                       .                      .                      .           .             .             .         .         0
10026 12022  23    .2028985470533371 1992   4.13   3.7 -1.48 .23 22                    .                       .                      .                      .           .             .             .         .         0
10026 12053  24   -.1325301229953766 1992   1.53  1.64  2.52 .28 23                    .                       .                      .                      .           .             .             .         .         0
10026 12082  25   .02777777798473835 1993    .93  2.03  5.87 .23 24                    .                       .                      .                      .           .             .             .         .         0
10026 12110  26   .06756756454706192 1993    .12 -3.43  6.42 .22 25                    .                       .                      .                      .           .             .             .         .         0
10026 12143  27   .17721518874168396 1993    2.3   .23  1.22 .25 26                    .                       .                      .                      .           .             .             .         .         0
10026 12173  28   .19354838132858276 1993  -3.05   -.7  2.61 .24 27                    .                       .                      .                      .           .             .             .         .         0
10026 12201  29   .06306306272745132 1993   2.89  1.96 -3.41 .22 28                    .                       .                      .                      .           .             .             .         .         0
10026 12234  30   .12711864709854126 1993    .31  -.31  2.62 .25 29                    .                       .                      .                      .           .             .             .         .         0
10026 12264  31   .04511278122663498 1993   -.34   .93  3.25 .24 30                    .                       .                      .                      .           .             .             .         .         0
10026 12296  32   .12230215966701508 1993   3.71   .31  -.45 .25 31                    .                       .                      .                      .           .             .             .         .         0
10026 12326  33  -.07692307978868485 1993   -.12  3.11  -.44 .26 32                    .                       .                      .                      .           .             .             .         .         0
10026 12355  34    .0763888880610466 1993   1.41  1.45 -1.54 .22 33                    .                       .                      .                      .           .             .             .         .         0
10026 12387  35  -.07741935551166534 1993  -1.89 -1.42  -.27 .25 34                    .                       .                      .                      .           .             .             .         .         0
10026 12418  36    .1538461595773697 1993   1.65  1.22   .57 .23 35                    .                       .                      .                      .           .             .             .         .         0
10026 12449  37   -.1090909093618393 1994   2.87   .15  2.09 .25 36                    .                       .                      .                      .           .             .             .         .         0
10026 12477  38  .040816325694322586 1994  -2.55  2.73 -1.45 .21 37                    .                       .                      .                      .           .             .             .         .         0
10026 12508  39  -.13071896135807037 1994  -4.78  -.98  1.29 .27 38                    .                       .                      .                      .           .             .             .         .         0
10026 12537  40  -.07518796622753143 1994    .68  -.92  1.68 .27 39                    .                       .                      .                      .           .             .             .         .         0
10026 12569  41   -.1869918704032898 1994    .58 -2.01    .2 .31 40                    .                       .                      .                      .           .             .             .         .         0
10026 12599  42  .009999999776482582 1994  -3.03  -.45  1.69 .31 41                    .                       .                      .                      .           .             .             .         .         0
10026 12628  43                    0 1994   2.82 -1.72   .62 .28 42                    .                       .                      .                      .           .             .             .         .         0
10026 12661  44  .019801979884505272 1994   4.01  1.34 -2.81 .37 43                    .                       .                      .                      .           .             .             .         .         0
10026 12691  45 -.009708737954497337 1994  -2.31  2.83 -1.91 .37 44                    .                       .                      .                      .           .             .             .         .         0
10026 12722  46   -.0882352963089943 1994   1.34 -2.35 -1.74 .38 45                    .                       .                      .                      .           .             .             .         .         0
10026 12752  47   .05376344174146652 1994  -4.04   .26  -.94 .37 46                    .                       .                      .                      .           .             .             .         .         0
10026 12782  48 -.051020409911870956 1994    .86   .04   .54 .44 47                    .                       .                      .                      .           .             .             .         .         0
10026 12814  49  -.07526881992816925 1995    1.8 -2.65   .81 .42 48                    .                       .                      .                      .           .             .             .         . .50427437
10026 12842  50     .075581394135952 1995   3.63  -.67  1.09  .4 49                    .                       .                      .                      .           .             .             .         . .50427437
10026 12873  51  -.10270269960165024 1995   2.19  -.69  -1.1 .46 50                    .                       .                      .                      .           .             .             .         . .50427437
10026 12901  52   .14457830786705017 1995   2.11  -.63  2.27 .44 51                    .                       .                      .                      .           .             .             .         . .50427437
10026 12934  53  .021052632480859756 1995    2.9 -2.21  1.72 .54 52                    .                       .                      .                      .           .             .             .         . .50427437
10026 12964  54   .04123711213469505 1995   2.72  2.93 -2.28 .47 53                    .                       .                      .                      .           .             .             .         . .50427437
10026 12995  55  -.06930693238973618 1995   3.72  2.09 -1.67 .45 54                    .                       .                      .                      .           .             .             .         . .50427437
10026 13026  56  .042553190141916275 1995    .55  1.59  2.71 .47 55                    .                       .                      .                      .           .             .             .         . .50427437
10026 13055  57 -.040816325694322586 1995   3.35 -2.11  -.75 .43 56                    .                       .                      .                      .           .             .             .         . .50427437
10026 13087  58  -.05319149047136307 1995  -1.52 -3.75  -.74 .47 57                    .                       .                      .                      .           .             .             .         . .50427437
10026 13117  59   .10112359374761581 1995   3.96 -1.17   .95 .42 58                    .                       .                      .                      .           .             .             .         . .50427437
10026 13146  60  -.10204081982374191 1995   1.03   .58   .87 .49 59  .011446257996319266    .0031083488575380336   .0007837813901823772 -.00017117708573134022  .011789645   .0018028422   .0006818898 .50427437 .50427437
10026 13179  61   .09090909361839294 1996   2.26 -2.62    .3 .43 60   .01141655651937715     .002967164165872884   .0006055615597711293  -.0019491555659077921   .02580142    -.00777397   .0001816685  .4482091   5.21823
10026 13208  62 -.010416666977107525 1996   1.33  1.88 -1.42 .39 60  .011900308081964553     .002763905517556863   .0003414133385293526 -.00025384844357286343   .01582741    .005196142  -.0004848069  .4105387   5.21823
10026 13237  63                    0 1996    .73  1.31  1.01 .39 60  .007687146241300398   -.0012732620443929611  -.0005641615953833017   -.000563244623076835  .005611617  -.0016679732 -.00056980323  .3933738   5.21823
10026 13269  64  .031578946858644485 1996   2.06  4.91 -3.91 .46 60  .007529811550781114    -.001830991260804364  -.0004555116839428207  -.0011657622466918014   .01551141   -.008990167   .0017810507  .4683023   5.21823
10026 13300  65    .0714285746216774 1996   2.36  3.05  -1.2 .42 60    .0079407465432455   -.0018103854215813886   -.001229417435213649  -.0040901289992197176   .01874016   -.005521676    .001475301  .4346938   5.21823
10026 13328  66  -.12380952388048172 1996  -1.14 -3.58  1.56  .4 60  .008528617858535856   -.0014406584047278966  -.0014911112030403912  -.0023809649517397722 -.009722624    .005157557  -.0023261334  .3931088   5.21823
10026 13361  67  -.11413043737411499 1996  -5.97 -3.84  4.45 .45 60  .010950893763645197 -.000036063405052529525  -.0010928401485301793    -.00905351148931477  -.06537683  .00013848348   -.004863138  .3798985   5.21823
10026 13391  68 .0061349691823124886 1996   2.77   2.3  -.46 .41 60  .011317748034082701    .0003493341034354797  -.0011856636247659256    -.01015029636184068  .031350162   .0008034684  .00054540526 .44269904   5.21823
10026 13422  69   .04878048598766327 1996   5.01  -.88 -3.15 .44 60  .011489058119879785    .0005700755382551095  -.0013789715986972436   -.008938277046662259   .05756018 -.00050166645   .0043437607 .50140226   5.21823
10026 13453  70  .023255813866853714 1996    .86 -4.44  5.12 .42 60  .011658735162414474    .0004988506544728838  -.0011809599963711376   -.009664512139540274  .010026513   -.002214897   -.006046515  .4217651   5.21823
10026 13482  71                    0 1996   6.25 -3.89  1.16 .41 60  .011786612659324326   .00039690356457086954  -.0010769792844097057   -.007566547962950346   .07366633   -.001543955   -.001249296  .4808731   5.21823
10026 13514  72   .22727273404598236 1996   -1.7   3.2   .89 .46 60  .011219465357253846      .00106821132613723  -.0011006322324798314    -.00820967580915348  -.01907309    .003418276  -.0009795626  .4433656   5.21823
10026 13545  73  -.03703703731298447 1997   4.98 -1.84 -1.65 .45 60    .0076026139279346     .004133372557213107 -.00009013771381250087   -.002937093672833596   .03786102   -.007605406  .00014872722  .4804043  5.417622
10026 13573  74 -.004807692486792803 1997   -.49  -2.9   5.2 .39 60 .0072888819067101875     .014147528188169979    .007218145173153877   -.003178988902958861 -.003571552    -.04102783     .03753435   .382935  5.417622
10026 13604  75 -.014492753893136978 1997  -5.02  -.38  3.81 .43 60   .00822528484509296     .016210580744074055    .010791101857272107  -.0037914964087542302  -.04129093   -.006160021      .0411141  .4236631  5.417622
10026 13634  76                    0 1997   4.04 -5.65  -.07 .43 60  .008598203322921504     .016092811849285245    .010372286211103494   -.004782104727757051   .03473674     -.0909244    -.00072606  .3730863  5.417622
10026 13664  77   .11764705926179886 1997   6.74  4.89 -3.87 .49 60  .008792893989605711     .015567131985001415    .009501344270253377    -.00437628726046675    .0592641     .07612327   -.036770202  .5886172  5.417622
10026 13695  78   .07894736528396606 1997    4.1  1.33  1.23 .37 60  .009027231813392806      .01590567580172512    .009505501431766018    -.00392141456528047   .03701165     .02115455    .011691767   .439858  5.417622
10026 13726  79  .024390242993831635 1997   7.33  -2.8   .82 .43 60  .008451853366378093     .015213053258285246    .010019612082444994   -.001391448185985307   .06195208    -.04259655    .008216082  .4575716  5.417622
10026 13755  80  -.01587301678955555 1997  -4.15  7.31  1.38 .41 60  .008388208804159199     .015244734234995989    .010029202709099341   -.001476808380188186  -.03481107       .111439      .0138403 .50046825  5.417622
10026 13787  81   .04838709533214569 1997   5.35  2.61   .01 .44 60  .009825254035005768     .013310332592056901    .009817734347560427   -.005714941567701748   .05256511    .034739967  .00009817734 .52740324  5.417622
10026 13818  82   .04615384712815285 1997   -3.8  -.68  1.95 .42 60  .009401765847729109     .013037602862270936     .00932731768750297    -.00382576671540542  -.03572671    -.00886557     .01818827   .393596  5.417622
10026 13846  83 -.022058824077248573 1997   2.98 -4.95   .79 .39 60  .008462178030529215      .01298676259084703    .008596374054801691  .00009111926405636767   .02521729    -.06428447    .006791136 .35772395  5.417622
10026 13879  84 -.015037594363093376 1997   1.32 -2.35  3.45 .48 60   .00767323133133011     .011553202790176857    .008497483325831196  -.0011324868901720388  .010128666   -.027150026     .02931632  .4922949  5.417622
10026 13909  85  -.12977099418640137 1998    .15 -1.16 -1.45 .43 60  .008432652745646118     .013249059907109792      .0105114580691476  -.0003319728418594674  .001264898    -.01536891   -.015241615  .4006544 4.6049457
10026 13937  86   .09649122506380081 1998   7.04     0  -.13 .39 60  .009679829145056329      .01530102908887609    .014174554010816803   -.003626232315944637     .068146             0   -.001842692  .4563033 4.6049457
10026 13969  87   .25200000405311584 1998   4.76  -.93  1.05 .39 60   .00992897214478818      .01537481895289052    .013535235197958824  -.0036411039628239297   .04726191   -.014298582    .014211996  .4371753 4.6049457
10026 13999  88  -.00319488812237978 1998    .73    .2   .74 .43 60  .011079744984311066     .015113591077757081    .014139403395187693   -.004235085918772419  .008088214    .003022718    .010463159  .4515741 4.6049457
10026 14028  89 -.009615384973585606 1998  -3.07 -3.74  4.16  .4 60  .012434543834965582     .015058242565961697     .01293565080603436   -.009422668601833764  -.03817405    -.05631783     .05381231  .3593204 4.6049457
10026 14060  90   .08090614527463913 1998   3.18 -3.16 -2.33 .41 60   .01227249254358975     .014821326011025208      .0141162450830164    -.01002398609141457   .03902653    -.04683539    -.03289085  .3693003 4.6049457
10026 14091  91  -.07784431427717209 1998  -2.46 -5.12  -.96  .4 60  .011875289263169104     .012738680302744899    .010479468771873066   -.008216211789862399  -.02921321    -.06522204    -.01006029 .29550445 4.6049457
10026 14122  92   -.1818181872367859 1998 -16.08 -5.31   3.4 .43 60  .011474942846727836     .012055990030511035     .00957861893172194   -.007309859488132307   -.1845171     -.0640173    .032567304  .2140329 4.6049457
10026 14152  93    .1746031790971756 1998   6.15  -.14 -3.31 .46 60  .010373365855938203     .011557784845239817     .00927005949250417   -.007178185350153804    .0637962    -.00161809   -.030683896  .4914942 4.6049457
10026 14182  94   .21621622145175934 1998   7.13 -3.29 -2.21 .32 60  .010599836986073372     .011852870833005442    .007237313324441011  -.0023769650189052723   .07557684    -.03899594   -.015994463  .3405864 4.6049457
10026 14213  95  -.07222222536802292 1998    6.1  1.07 -3.15 .31 60  .011615376347231513      .00976441323594587    .005602760197684415   -.002002426278449248   .07085379    .010447923   -.017648695   .373653 4.6049457
10026 14244  96     .071856290102005 1998   6.16  -.35 -4.46 .38 60  .011083616097553841     .009593069876276507    .006630169213786634  -.0033149719985044856   .06827507   -.003357574   -.029570555 .41534695 4.6049457
10026 14273  97   .08379888534545898 1999    3.5   .37 -4.03 .35 60   .01097009973453511     .008733551926613651    .005374829835790114   -.004846160989898674   .03839535   .0032314144   -.021660564  .3699662 4.7597466
10026 14301  98  -.12886597216129303 1999  -4.08 -5.67   1.4 .35 60  .011523481211702859     .009301770918655345   .0061530297213067625  -.0017018709672941956   -.0470158    -.05274104    .008614241  .2588574 4.7597466
10026 14334  99 -.047337278723716736 1999   3.45 -3.93 -2.65 .43 60  .012140977552255948     .009330856072121621     .00686896805546518   -.004129815266759631   .04188637   -.036670264   -.018202767 .41701335 4.7597466
10026 14364 100   .08074533939361572 1999   4.33     4  2.53 .37 60  .011664151151841606      .00969045683031407    .007108625775940371   -.002520592684405517   .05050577     .03876183    .017984822  .4772524 4.7597466
end
format %d date


the ce i got is the expected monthly return through 3-factor model. Now, i want to convert this variable into annual returns as i need the cost of equity on annual basis to merge it with another file. Problem is i donot know how to do it because of the following:
1. Fama and french factors (mktrf smb hml rf) are montly returns (this is what i understand) so the returns that i got are monthly (i beleive), then if i have to calculate the annual returns i should add these monthy returns, so


Code:
bys permno year: egen returns=total(ce)
Otherwise, if i have to calculate cumulative returns then I did this


Code:
bys permno : asrol ce, stat(product) add(1) window(month 12) gen(ce_cum)
However, the results I get from these two are much higher to be the cost of equity capital and much different from the ce i calculated.

I do not know if I applied the rangestat correctly, or which method is the right one and if there is a mistake in my calculations. Any help in this regard is much appreciated.


regards,