Year of survey minus year of birth is equal the age at the time of the survey.

Export your year of birth to excel, do the math and create a new variable "age" in your database.

Exactly. Take into account, though, that it is an approximation, because of the different days of birth within the same year.

Regards

The command in Stata is straightforward:

generate age = yearsurvey - yearbirth

Obviously, you have to adapt this to the names of the two latter variables in your data.

Thank you everyone. I calculated age using generate age = yearsurvey - yearbirth

Try to use CMC formula. This will give more accurate age than yearS-YearB.

@Sumoni can you be more specific on your suggestion please?

Sure Andres, CMC is century month code. It calculate age considering month and year of survey and birth. More rectification came when it included date of birth and survey too. Now this is known as CDC = century day code.

Regards

Thank you @Sumoni. I assumed in my answer that the data that @Selva Mani is using only has yearly information, not monthly or daily one. But obviously, the more precision, the better, whenever data allows for that.

Regards

The China Health and Retirement Longitudinal Study (CHARLS) aims to collect a high quality nationally representative sample of Chinese residents ages