Dear Stata users,

I'm struggling to find a robust way to compare the autocorrelations of two earnings surprise measurements, one being seasonal random walk (srw) error and other forecast error. I know they both are autocorrelated and that srw errors are probably more autocorrelated than forecast errors (by using corr and reg commands with srw_error / forecast error as dependent and 4 lags as independent variables), but I need a statistical test to compare those autocorrelations directly. I wasn't able to make Breusch-Godfrey test work.

My data looks as follows (for forecast errors it's the same).

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input str8 ticker double date float(srw_error srw_error_lag srw_error_lag2 srw_error_lag3 srw_error_lag4)
"A"   14658             .             .             .             .             .
"A"   14746             .             .             .             .             .
"A"   14839             .             .             .             .             .
"A"   14934             .             .             .             .             .
"A"   16481  -.0013039935             .             .             .             .
"A"   16572  -.0014159292  -.0013039935             .             .             .
"A"   16663   -.001526232  -.0014159292  -.0013039935             .             .
"A"   16754   -.003549921   -.001526232  -.0014159292  -.0013039935             .
"A"   16845    .005345211   -.003549921   -.001526232  -.0014159292  -.0013039935
"A"   16936    .009302326    .005345211   -.003549921   -.001526232  -.0014159292
"A"   17027    .006957866    .009302326    .005345211   -.003549921   -.001526232
"A"   17119    .004268293    .006957866    .009302326    .005345211   -.003549921
"A"   17212   .0020390328    .004268293    .006957866    .009302326    .005345211
"A"   17300   .0007662835   .0020390328    .004268293    .006957866    .009302326
"A"   17392   .0007130125   .0007662835   .0020390328    .004268293    .006957866
"A"   17485   .0002938584   .0007130125   .0007662835   .0020390328    .004268293
"A"   17666    .003684372   .0002938584   .0007130125   .0007662835   .0020390328
"A"   17758    .002702703    .003684372   .0002938584   .0007130125   .0007662835
"A"   17850    .003654398    .002702703    .003684372   .0002938584   .0007130125
"A"   17945   -.009404388    .003654398    .002702703    .003684372   .0002938584
"A"   18031   -.011942175   -.009404388    .003654398    .002702703    .003684372
"A"   18126    -.01037118   -.011942175   -.009404388    .003654398    .002702703
"A"   18214   -.013999066    -.01037118   -.011942175   -.009404388    .003654398
"A"   18305    .009326425   -.013999066    -.01037118   -.011942175   -.009404388
"A"   18399    .015600624    .009326425   -.013999066    -.01037118   -.011942175
"A"   18490    .016434893    .015600624    .009326425   -.013999066    -.01037118
"A"   18578    .012629163    .016434893    .015600624    .009326425   -.013999066
"A"   18672     .00756794    .012629163    .016434893    .015600624    .009326425
"A"   18760    .009727016     .00756794    .012629163    .016434893    .015600624
"A"   18854    .008005569    .009727016     .00756794    .012629163    .016434893
"A"   18946    .005279244    .008005569    .009727016     .00756794    .012629163
"A"   19038     .00209351    .005279244    .008005569    .009727016     .00756794
"A"   19127   .0008135042     .00209351    .005279244    .008005569    .009727016
"A"   19220   .0005465974   .0008135042     .00209351    .005279244    .008005569
"A"   19316   .0005299417   .0005465974   .0008135042     .00209351    .005279244
"A"   19403  -.0013452915   .0005299417   .0005465974   .0008135042     .00209351
"A"   19492   -.000243843  -.0013452915   .0005299417   .0005465974   .0008135042
"A"   19584   -.002732919   -.000243843  -.0013452915   .0005299417   .0005465974
"A"   19676  -.0013546464   -.002732919   -.000243843  -.0013452915   .0005299417
"A"   19767   .0008871147  -.0013546464   -.002732919   -.000243843  -.0013452915
"A"   19857  -.0011904762   .0008871147  -.0013546464   -.002732919   -.000243843
"A"   19949   .0021701388  -.0011904762   .0008871147  -.0013546464   -.002732919
"A"   20044   .0013714733   .0021701388  -.0011904762   .0008871147  -.0013546464
"AAI" 16461             .             .             .             .             .
"AAI" 16643             .             .             .             .             .
"AAI" 16736             .             .             .             .             .
"AAI" 16826             .             .             .             .             .
"AAI" 16918   -.011641444             .             .             .             .
"AAI" 17009           .02   -.011641444             .             .             .
"AAI" 17100   -.003548616           .02   -.011641444             .             .
"AAI" 17192  -.0029006526   -.003548616           .02   -.011641444             .
"AAI" 17281    .008614977  -.0029006526   -.003548616           .02   -.011641444
"AAI" 17373   .0028797695    .008614977  -.0029006526   -.003548616           .02
"AAI" 17828    -.04528302   .0028797695    .008614977  -.0029006526   -.003548616
"AAI" 18009     .01988401    -.04528302   .0028797695    .008614977  -.0029006526
"AAI" 18100     .02624894     .01988401    -.04528302   .0028797695    .008614977
"AAI" 18191   -.027884616     .02624894     .01988401    -.04528302   .0028797695
"AAI" 18289     .13653846   -.027884616     .02624894     .01988401    -.04528302
"AAI" 18373     -.0608365     .13653846   -.027884616     .02624894     .01988401
"AAI" 18464    -.01710731     -.0608365     .13653846   -.027884616     .02624894
"AAL" 13258             .             .             .             .             .
"AAL" 19751             .             .             .             .             .
"AAL" 19837             .             .             .             .             .
"AAL" 19928             .             .             .             .             .
"AAL" 20019           .08             .             .             .             .
"AAN" 18742             .             .             .             .             .
"AAN" 18833             .             .             .             .             .
"AAN" 18924             .             .             .             .             .
"AAN" 19291             .             .             .             .             .
"AAN" 19473    .004711425             .             .             .             .
"AAN" 19563    .003265602    .004711425             .             .             .
"AAN" 19655   .0014566643    .003265602    .004711425             .             .
"AAN" 19761   -.005710207   .0014566643    .003265602    .004711425             .
"AAN" 19838   -.004991088   -.005710207   .0014566643    .003265602    .004711425
"AAN" 19929  -.0045107566   -.004991088   -.005710207   .0014566643    .003265602
"AAN" 20020   -.000349162  -.0045107566   -.004991088   -.005710207   .0014566643
"AAP" 16483             .             .             .             .             .
"AAP" 16574             .             .             .             .             .
"AAP" 16659             .             .             .             .             .
"AAP" 16743             .             .             .             .             .
"AAP" 16939    .008269827             .             .             .             .
"AAP" 17023  -.0006742605    .008269827             .             .             .
"AAP" 17107 -.00056385674  -.0006742605    .008269827             .             .
"AAP" 17212   -.006024096 -.00056385674  -.0006742605    .008269827             .
"AAP" 17302   .0007392804   -.006024096 -.00056385674  -.0006742605    .008269827
"AAP" 17386   .0016545334   .0007392804   -.006024096 -.00056385674  -.0006742605
"AAP" 17470   .0014208582   .0016545334   .0007392804   -.006024096 -.00056385674
"AAP" 17667    .013827289   .0014208582   .0016545334   .0007392804   -.006024096
"AAP" 17750   .0019161677    .013827289   .0014208582   .0016545334   .0007392804
"AAP" 17834  -.0014380213   .0019161677    .013827289   .0014208582   .0016545334
"AAP" 17946   -.003139717  -.0014380213   .0019161677    .013827289   .0014208582
"AAP" 18037    .004735128   -.003139717  -.0014380213   .0019161677    .013827289
"AAP" 18121    .002391772    .004735128   -.003139717  -.0014380213   .0019161677
"AAP" 18212    .003448276    .002391772    .004735128   -.003139717  -.0014380213
"AAP" 18310    -.00350365    .003448276    .002391772    .004735128   -.003139717
"AAP" 18401   .0042047985    -.00350365    .003448276    .002391772    .004735128
"AAP" 18485    .005939288   .0042047985    -.00350365    .003448276    .002391772
"AAP" 18576    .008822002    .005939288   .0042047985    -.00350365    .003448276
"AAP" 18667   .0044106836    .008822002    .005939288   .0042047985    -.00350365
"AAP" 18765    .003523453   .0044106836    .008822002    .005939288   .0042047985
end
format %d date

Kind regards,

Frank