Dear all

May you assist since I am not very familiar with lag functions. I am working with longitudinal data (multiple records per person) and I would like to create a new variable "diff" based on the previous record. So "within personid" : gen (date _episode - date_episode "of previous record") = diff. to look like this

personid date_episode diff
1 2/05/2020 0
1 5/09/2020 126
1 8/10/2020 33
1 9/11/2020 32