Which variables should I use to measure age and date of birth?

There are two key age variables – w_dvage and w_age_dv. The variable w_dvage is the person’s age, in number of completed years, computed during the interview and used for filtering age-triggered questions. So, if you want to understand or check who gets asked any of the age triggered questions you should use w_dvage. The corresponding date of birth variables are birthy, birthm. But this variable is not checked for longitudinal consistency or even consistency across multiple age reports. The data team checks the information on age collected from different sources and produces the variable,  w_age_dv. The corresponding date of birth variables are doby_dv and dobm_dv.