Deborah Brunning

Statistics New Zealand

Experiences with the design and analysis of longitudinal data at Statistics New Zealand

Prior to the turn of the century, Statistics New Zealand had little experience with the design and analysis of longitudinal data. However over the last decade, the interest of policy makers in New Zealand, like their counterparts in many other countries, has identified a need for more information to enable them to study patterns and dynamics beyond what is achievable with repeated cross-sectional snapshots. To respond to this need over the past 10 years Statistics New Zealand has: designed and run 7 waves of an 8 wave survey to measure income and employment dynamics (known as SoFIE); conducted, in partnership with the Department of Labour, 2 waves of a 3 wave longitudinal survey to measure migrant's settlement experiences in New Zealand (LISNZ); developed a longitudinal business database, by combining data from a number of sources; and developed a dataset which enables us to examine the longitudinal patterns and dynamics of both employers and employees using administrative data from the taxation system (LEED).

In this paper we will discuss our experiences with these developments. There have been both achievements and significant challenges encountered in this work, in areas such as design and implementation of collection methodologies, use of computer assisted methods and confidentiality and data access. We will discuss how these experiences are influencing our thinking about future longitudinal data collections in Statistics New Zealand.