Using address histories to improve the link rates of surveys in the Integrated Data Infrastructure (IDI)

Abstract

Stats NZ’s Integrated Data Infrastructure (IDI) is a linked longitudinal database combining administrative and survey data. Initially, the IDI contained a small number of administrative datasets from key government agencies, which generally contained good quality identifying information such as nam es and date of birth. As a result, the methodologies developed to link these datasets together relied heavily on these variables, and yielded high link rates while maintaining good quality links. When survey datasets were later added, the link rates achieved were lower than that of administrative datasets, due to poor quality names and the underutilisation of geographic information. This indicated there were improvements to be made to the linking methodology used to link survey data in the IDI. Stats NZ underwent extensive consultation with the research community on their requirements for the expansion of the IDI (IDI2). A key finding from the consultation was that researchers wanted improved survey linkage. This paper outlines how the address history of individuals were used to increase the link rate of surveys in the IDI.