Esttab and compare if coefficients of two regressions are statistically different

[Hugo Rocha]

Dear all,

This looks like an extremely basic question but I am having issues with "esttab" and my saved "estimation results". I am trying to recheck my estimations and I am using the esttab command as follows:

 esttab high_tech low_tech

Nevertheless, I get that the estimations result were not found. Do you know what is the problem?

Also, I am interested in comparing the coefficients (betas) for my regressions in low_tech and high_tech to see if they are statistically different? Is there a quick way of doing it? Thank you!

 * Example generated by -dataex-. To install: ssc install dataex
clear
input int(country1 year) long Employment double(Wages OutputINDSTAT4 ValueAdded) byte(_est_all _est_low_tech _est_high_tech)
4 1973  1287 . . . 0 0 0
4 1973     0 . . . 0 0 0
4 1973 12555 . . . 0 0 0
4 1973     0 . . . 0 0 0
4 1973  4321 . . . 0 0 0
4 1973   725 . . . 0 0 0
4 1973     . . . . 0 0 0
4 1973  1941 . . . 0 0 0
4 1974     0 . . . 0 0 0
4 1974 14243 . . . 0 0 0
4 1974  1326 . . . 0 0 0
4 1974   720 . . . 0 0 0
4 1974     0 . . . 0 0 0
4 1974  4845 . . . 0 0 0
4 1974  2044 . . . 0 0 0
4 1974     . . . . 0 0 0
4 1975  1447 . . . 0 0 0
4 1975     0 . . . 0 0 0
4 1975 17202 . . . 0 0 0
4 1975     0 . . . 0 0 0
4 1975  5103 . . . 0 0 0
4 1975  2321 . . . 0 0 0
4 1975     . . . . 0 0 0
4 1975   874 . . . 0 0 0
4 1976     0 . . . 0 0 0
4 1976 20520 . . . 0 0 0
4 1976   840 . . . 0 0 0
4 1976  2317 . . . 0 0 0
4 1976  1465 . . . 0 0 0
4 1976     . . . . 0 0 0
4 1976  4540 . . . 0 0 0
4 1976     0 . . . 0 0 0
4 1977     0 . . . 0 0 0
4 1977     . . . . 0 0 0
4 1977  2240 . . . 0 0 0
4 1977  6309 . . . 0 0 0
4 1977 20540 . . . 0 0 0
4 1977     0 . . . 0 0 0
4 1977   920 . . . 0 0 0
4 1977  1747 . . . 0 0 0
4 1978     0 . . . 0 0 0
4 1978     . . . . 0 0 0
4 1978     0 . . . 0 0 0
4 1978  1772 . . . 0 0 0
4 1978  6413 . . . 0 0 0
4 1978   992 . . . 0 0 0
4 1978 22889 . . . 0 0 0
4 1978  2583 . . . 0 0 0
4 1979  2218 . . . 0 0 0
4 1979 23733 . . . 0 0 0
4 1979     . . . . 0 0 0
4 1979   899 . . . 0 0 0
4 1979  2526 . . . 0 0 0
4 1979  6006 . . . 0 0 0
4 1979     0 . . . 0 0 0
4 1979     0 . . . 0 0 0
4 1980     0 . . . 0 0 0
4 1980     . . . . 0 0 0
4 1980  5672 . . . 0 0 0
4 1980  2661 . . . 0 0 0
4 1980     0 . . . 0 0 0
4 1980  2231 . . . 0 0 0
4 1980 20438 . . . 0 0 0
4 1980   768 . . . 0 0 0
4 1981     . . . . 0 0 0
4 1981   697 . . . 0 0 0
4 1981  8481 . . . 0 0 0
4 1981     0 . . . 0 0 0
4 1981  3468 . . . 0 0 0
4 1981 15068 . . . 0 0 0
4 1981  2230 . . . 0 0 0
4 1981     0 . . . 0 0 0
4 1982  6866 . . . 0 0 0
4 1982   584 . . . 0 0 0
4 1982  1810 . . . 0 0 0
4 1982 13387 . . . 0 0 0
4 1982  3211 . . . 0 0 0
4 1982     0 . . . 0 0 0
4 1982     . . . . 0 0 0
4 1982     0 . . . 0 0 0
4 1983   942 . . . 0 0 0
4 1983     . . . . 0 0 0
4 1983   157 . . . 0 0 0
4 1983  1975 . . . 0 0 0
4 1983  3567 . . . 0 0 0
4 1983  5080 . . . 0 0 0
4 1983     0 . . . 0 0 0
4 1983 10067 . . . 0 0 0
4 1984   157 . . . 0 0 0
4 1984  4078 . . . 0 0 0
4 1984  5187 . . . 0 0 0
4 1984   949 . . . 0 0 0
4 1984  1235 . . . 0 0 0
4 1984 10208 . . . 0 0 0
4 1984     0 . . . 0 0 0
4 1984     . . . . 0 0 0
4 1985 10468 . . . 0 0 0
4 1985  2023 . . . 0 0 0
4 1985     0 . . . 0 0 0
4 1985     . . . . 0 0 0
end

[Carlo Lazzaro]

Hugo:
-codebook- outcome is telling me that .-Wages-, -OutputINDSTAT4-, and -ValueAdded- variables have all missing values.
If this situation occurs in your original dataset, due to casewise deletion, Stata does not return any coefficients.

[Hugo Rocha]

Hugo:
-codebook- outcome is telling me that .-Wages-, -OutputINDSTAT4-, and -ValueAdded- variables have all missing values.
If this situation occurs in your original dataset, due to casewise deletion, Stata does not return any coefficients.

Thank you for your response. But I ran all the regressions before and it also shows me that not all variables are missing. In fact, I have around 90,000 not missing

[Carlo Lazzaro]

Hugo:
I would give -statsby- a shot and see if the problem still creeps up-

[Hugo Rocha]

Thank you! I am trying that!