In a dataset of multiple variable lists, I would like to multiply the value of only selected variables in one variable list by 4. Namely, I want to keep the observations unchaged if the observation concerns the age_group of <1 years and 95 plus (age_group variable list is not numeric). For all the other cases, I am trying to multiply the observation values by 4. I initially used this command: gen new_var = old_var * 4 if age_group != "<1 year" but I cannot incorporate 95 plus age group in this command. Also, in a new variable list, observations for <1 age group are deleted, while I would just like to keep the previous value. Thanks!