Generate flag variable

[Diana Rossi]

Dear all,

I've replaced the missing values on a variable using the Lag-2 as follows:

tsset idauniq year

sort idauniq year

replace eqtotinc_CPI18 = L2.eqtotinc_bu_s / CPI_base_2018  if missing(eqtotinc_CPI18)

I would now like to generate a flag variable for when eqtotinc_CPI18 has been replaced using the lag.

Thank you very much,
Diana

[Igor Paploski]

Hi Diana,

It would be easier to help if you shared a snippet of the dataset using dataex. Please read the FAQ (section 12) for more info on that.

One option would be to clone eqtotinc_CPI18 before replacing it and them comparing the old and new eqtotinc_CPI18: whatever is different was replaced by your code. Something like:

clonevar eqtotinc_REF = eqtotinc_CPI18
replace eqtotinc_CPI18 = L2.eqtotinc_bu_s / CPI_base_2018  if missing(eqtotinc_CPI18)
gen flag = (eqtotinc_REF != eqtotinc_CPI18)

Best;

[William Lisowski]

Generate the flag first, then replace the value.

generate flag = missing(eqtotinc_CPI18)
replace eqtotinc_CPI18 = L2.eqtotinc_bu_s / CPI_base_2018  if flag