Carryforward command

[Clara Nelson]

Hi,

I am trying to use the carryforward command to copy Ethnicity values from one wave (year) to the next for each individual in panel data per the below code but it says that zero real changes are made. Any idea why this is happening?

ssc install carryforward
sort pidp
by pidp: carryforward Ethnicity, replace

[George Ford]

probably need to bys by year too.