Codes

This is a 18-character string variable.

Description

PERSONID is an identification variable constructed by IPUMS using the reference ID variable (REFID) from the public use files. The original variable identifying individuals uniquely across samples is composed of alpha-numerics, whereas PERSONID used an algorithm to create unique numeric values for each individual. Each digit was expanded to 2 digits. Numeric digits were given a leading zero. For example, the digit 2 would be converted to 02. Letters would be converted by the ordinal of the letter plus ten. For example, A would be converted to 11, B to 12, C to 13 and so on. It is possible to identify individuals in different survey years within the same decade.

IPUMS-SESTAT has set PERSONID as a character string for statistical packages to more easily read in the values.

Users should note that some respondents are interviewed over time, allowing the possibility for longitudinal data analysis. Please see our User Note on Longitudinal Data.

Comparability

This variable is comparable across available years and surveys.

Universe

Availability