. gen Y = income/ 10000
(145 missing values generated)

. gen K=fixedassets/10000
(1 missing value generated)

. gen L=payemployeecash/10000
(1 missing value generated)

. gen M=mediafee/10000

. gen lnY = ln(Y + 1)
(146 missing values generated)

. gen lnL = ln(L + 1)
(1 missing value generated)

. gen lnM = ln(M + 1)
(25 missing values generated)

. gen lnK = ln(K + 1)
(1 missing value generated)

. foreach i in lnY lnL lnM lnK {
  2.     drop if `i' == .
  3.     cap drop TFP_* _TFP*
  4. }
(146 observations deleted)
(1 observation deleted)
(24 observations deleted)
(1 observation deleted)


. xtset symbol enddate
       panel variable:  symbol (unbalanced)
        time variable:  enddate, 20071231 to 20191231, but with gaps
                delta:  1 unit

. levpet lnY, free(lnL) proxy(lnM) capital(lnK)
no observations