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Labour Supply in New Zealand and the 2010 Tax and Transfer Changes

Publication Details

  • Labour Supply in New Zealand and the 2010 Tax and Transfer Changes (WP 15/13)
  • Published: 8 Sep 2015
  • Status: Current
  • Authors: Creedy, John; Mok, Penny
  • Pages: (2),vi,33
  • ISBN: 978-0-908337-02-6 (Online)
  • Ref. No: WP 15/13
  • Pub. type: Working Papers
  • JEL Classification: C25; J22

Labour Supply in New Zealand and the 2010 Tax and Transfer Changes

Published 8 Sep 2015

Authors: John Creedy and Penny Mok


This paper examines the simulated labour supply responses to the personal tax and transfer policy changes introduced in New Zealand in 2010, and the implications for revenue and income distribution. The main changes examined are the increase in the GST rate from 12.5 to 15 per cent, along with reductions in personal income tax rates and increases in the main benefit payments and assistance to families with children, to compensate for the rise in GST. The simulated labour supply responses were obtained using the Treasury's behavioural microsimulation model, TaxWell-B. The 2009/10 Household Economic Survey (HES) was used. The combined effect of all policy changes is to increase average labour supply slightly for all demographic groups. Labour force participation of sole parents is simulated to increase by 0.86 percentage points. In considering separate components, the change in income tax rates is found to have the largest effect on labour supply. This is not surprising given that it affected a large proportion of the population while the changes to the benefit system and assistance to families with children apply only to certain groups. The reforms are found to be approximately distribution neutral, in terms of the Gini inequality measure of after-tax income per adult equivalent person.


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Executive Summary

1 Introduction

2 The 2010 tax changes

3 The Treasury's Microsimulation Model

4 Simulated labour supply responses

5 Tax and revenue changes

6 Income distribution

7 The effects of separate policy changes

8 Conclusions


twp15-13.pdf (401 KB) pp. (2),i-iv,1-29


We should like to thank Norman Gemmell, Michelle Harding, Angela Mellish, Joseph Mercante, Suzy Morrissey, and Hemant Passi for comments on an earlier version of this paper. We have also benefited from comments by participants at NZAE July 2015 and a seminar in NZ Treasury.


The views, opinions, findings, and conclusions or recommendations expressed in this Working Paper are strictly those of the author(s). They do not necessarily reflect the views of the New Zealand Treasury or the New Zealand Government. The New Zealand Treasury and the New Zealand Government take no responsibility for any errors or omissions in, or for the correctness of, the information contained in these working papers. The paper is presented not as policy, but with a view to inform and stimulate wider debate.

Access to the data used in this paper was provided by Statistics New Zealand in accordance with security and confidentiality provisions of the Statistics Act 1975. The results presented in this study are the work of the authors, not Statistics New Zealand


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