Hi everyone,
I am new in Statalist. Thanks in advance for helping me!
I would like to ask you about the interpretation of the following xtsum table. My sample contains 3449 firms and T = 12 time periods. The panel is unbalanced since a firm that exit the sample never reenters; moreover a firm exit the sample because it makes no sales in a given year (possible attrition bias). Finally firms are observed starting from different time periods: it could be that a firm enters the sample in t=5, in t=1 or whatever.
What I do not understand is the reason why N, n and T are different for each variable in xtsum. Is it simply due to the unbalancedness of the panel?
P.s. in order to give complete info, I also copy paste the result from STATA directly.
Thank you,
Federico
I am new in Statalist. Thanks in advance for helping me!
I would like to ask you about the interpretation of the following xtsum table. My sample contains 3449 firms and T = 12 time periods. The panel is unbalanced since a firm that exit the sample never reenters; moreover a firm exit the sample because it makes no sales in a given year (possible attrition bias). Finally firms are observed starting from different time periods: it could be that a firm enters the sample in t=5, in t=1 or whatever.
What I do not understand is the reason why N, n and T are different for each variable in xtsum. Is it simply due to the unbalancedness of the panel?
P.s. in order to give complete info, I also copy paste the result from STATA directly.
Code:
Variable | Mean Std. Dev. Min Max | Observations -----------------+--------------------------------------------+---------------- t overall | 6.765197 3.439797 1 12 | N = 28360 between | 2.449812 1.5 12 | n = 3449 within | 3.089224 1.265197 12.2652 | T-bar = 8.22267 | | id_firm overall | 3253.188 2150.782 1 10070 | N = 28360 between | 2258.51 1 10070 | n = 3449 within | 0 3253.188 3253.188 | T-bar = 8.22267 | | salesf~m overall | 69405.53 637158.5 .0100969 1.91e+07 | N = 27542 between | 496200.5 .0101238 1.44e+07 | n = 3449 within | 194191.3 -8507032 5134997 | T-bar = 7.9855 | | age overall | 27.27154 23.67263 1 107 | N = 28360 between | 22.49973 1 101.5 | n = 3449 within | 3.089224 21.77154 32.77154 | T-bar = 8.22267 | | newmol overall | .0422916 .2012575 0 1 | N = 25537 between | .1127242 0 1 | n = 3381 within | .1647175 -.8667993 .9513825 | T-bar = 7.55309 | | newmol~m overall | .2407753 .427563 0 1 | N = 24093 between | .300853 0 1 | n = 3050 within | .2978449 -.6683156 1.149866 | T-bar = 7.89934 | | number overall | 27.82434 94.3868 1 2045 | N = 27542 between | 77.40525 1 1948.333 | n = 3449 within | 12.00478 -275.1757 331.8243 | T-bar = 7.9855 | | inflow overall | 1.75221 6.222528 0 199 | N = 24093 between | 4.839961 0 104.7273 | n = 3050 within | 2.978054 -41.24779 116.3886 | T-bar = 7.89934 | | salesi~t overall | 686.9673 8009.415 0 494231.2 | N = 24093 between | 4221.593 0 95303.28 | n = 3050 within | 6283.8 -84693.08 431932.1 | T-bar = 7.89934 | | outflow overall | 1.793176 7.088856 0 259 | N = 24093 between | 5.553401 0 136 | n = 3050 within | 2.953235 -58.75228 124.7932 | T-bar = 7.89934 | | atcmain overall | .6957304 .2972208 .0494371 1 | N = 27542 between | .2690053 .0744431 1 | n = 3449 within | .0960921 .2015287 1.431768 | T-bar = 7.9855 | | deathf~m overall | -14.92422 35.46399 -100 0 | N = 28360 between | 29.92316 -99.5 -8.25 | n = 3449 within | 31.30806 -105.6742 51.40911 | T-bar = 8.22267 | | lratio overall | -.0295049 .5119096 -2.989596 1.998053 | N = 24093 between | .4940006 -2.956451 1.974946 | n = 3050 within | .4153589 -2.802703 2.688072 | T-bar = 7.89934 | | nrecall overall | .1480285 .9719849 0 59 | N = 27542 between | .5405977 0 21.75 | n = 3449 within | .7198124 -21.60197 53.23136 | T-bar = 7.9855 | | s_it overall | .9711566 .1673693 0 1 | N = 28360 between | .1424335 .5 1 | n = 3449 within | .1435737 .0544899 1.471157 | T-bar = 8.22267
Federico
Comment