xtserial is a user-written command used to test for serial correlation in panel data models.
Here's the text you can use to install xtserial in Stata: install xtserial stata
ssc install xtserial Or, if you prefer to install from the search results: xtserial is a user-written command used to test
findit xtserial Then click on the link to install from SSC (Statistical Software Components). install xtserial stata