Given that a future linked employer-employee database may use Business Demography data as a backbone:
This analysis uses employer-based data from Statistics New Zealand's Business Demography Statistics (BDS) database for the period 1994-2001.
CAUTION: Article is behind a pay-wall.
Carroll, Nick; Dean Hyslop, David C. Maré, Jason Timmins and Julian Wood. 2002. "An Analysis of New Zealand's Business Demography Database," New Zealand Economic Papers, 36:1, pp. 59-62.