Modelled Territorial Authority Gross Domestic Product for New Zealand

Peter Ellis

June 2016

Today’s content

  • Modelling TA GDP
  • Accessing the data
  • Example analysis

Modelling TA GDP

The Challenge

  • Consistent with National and Regional Tier 1 GDP
  • Detailed data available for re-use
  • Source code and method open for critique and improvement
  • Easy interactive access

The data

  • Business Demography Statistics
  • Linked Employer - Employee Database
  • Regional GDP
  • National GDP

The method (bottom up)

  • reconcile the various earnings measures
  • scale up employee numbers to earnings
  • scale up earnings to GDP

The method (alternative, top down version)

  • reconcile the two GDP measures
  • allocate any ambiguity on basis of earnings
  • allocate any remaining ambiguity on basis of employees


Commuter correction

  • earnings only published by place of residence
  • use the Census 2013 to reallocate earnings on basis of commuting
  • known area for future improvement


  • Earnings a good indicator of value added
  • Employee numbers a good indicator of earnings
  • No interaction between TA and earnings:GDP ratio for specified industry
  • No interation between Region/TA and inter-industry relative earnings:GDP ratios of industries
  • Commuter patterns unchanging and not industry-specific
  • Price movements not industry-specific
  • Price movements not region-specific

Accessing the data