Panel data - dropping cross section based on missing values

[Pratap Pundir]

In a panel dataset, there are companies with revenues for multiple years.

I would like to drop all companies if their revenue information is missing for any year.

Is there a simple way to achieve this?

In SQL, I would do something like:

DELETE FROM table WHERE company_id IN (SELECT DISTINCT company_id WHERE sales(t)=0 AND sales(t-1)>0)

[Carlo Lazzaro]

Pratap:
dropping (missing) observations in not a good habit, as missingness can be informative.
That said, you may want to consider something along the following lines:

set obs 10
g panelid=1 in 1/5
replace panelid=2 if panelid==.
g revenue=1000*runiform() in 1/8
bysort panelid: gen flag=1 if revenue==.
replace flag=0 if flag==.
bysort panelid: egen total=total( flag )
drop if total>0
drop flag
drop total
list

     +--------------------+
     | panelid    revenue |
     |--------------------|
  1. |       1   348.8717 |
  2. |       1   266.8857 |
  3. |       1   136.6463 |
  4. |       1   28.55687 |
  5. |       1   868.9333 |
     +--------------------


.

[Pratap Pundir]

Thanks Carlos!

Could I simply go:

gen flag = 0
replace flag = 1 if revenue == .
bysort company_id: egen total=total(flag)
drop if total > 0
drop flag total

[Carlo Lazzaro]

Yes.