Video | Agriculture | Confidence | Economy | Energy | Employment | Finance | Media | Property | RBNZ | Science | SOEs | Tax | Technology | Telecoms | Tourism | Transport | Search


New app. shows cost of earning an extra dollar

New app. shows cost of earning an extra dollar

Press Release: Australian National University

Steve Thomas

15 May 2014

A new web app. released today, on Budget Day—the New Zealand Tax and Welfare Calculator (NZTWC)—helps New Zealand households better understand how the tax and welfare system impacts them. The app. can be accessed through:

The app. allows users to see what share of income they pay in tax (average tax rate), and the additional tax burden on earning an extra dollar from the income tax system and the withdrawal of tax credits (effective marginal tax rate).

“It is important for households to understand what these costs are because they affect decisions such as, whether to enter the labour force, whether to work longer hours, to take up a higher paying job, or to undertake further study,” says Steve Thomas, a New Zealand PhD Scholar at The Australian National University’s Crawford School of Public Policy, who designed the app. with two fellow ANU students.

With the taxable income of the primary and secondary earner in a household, the NZTWC currently calculates how much income tax a household pays and how much it is entitled to receive in Family Tax Credits, In-Work Tax Credits and the Parental Tax Credit (which are part of Working for Families). The Labour Party’s proposed ‘Best Start’ baby bonus, which would replace the Parental Tax Credit, can also be included.

“With this information, the NZTWC determines the overall sacrifice each earner makes in taxation—according to his or her average tax rate—and the cost of earning an extra dollar for each earner—according to his or her effective marginal tax rate,” says Thomas.

For example, for the average New Zealand household earning around $85,000:

• The effective marginal tax rate on the primary earner is 34.7% for a sole income household with no children—paying $18,970 a year in income tax.

• For a two-income household, the effective marginal tax rate is 31.7% for the primary earner and 19.2% per cent for the secondary earner, assuming income is apportioned two-thirds, one-third. The household pays about $14,000 in income tax.

• For the same household with three children (a new born, a 2 year old and a 5 year old) the NZTWC shows that the effective tax rates increase to 52.9% for the primary earner and 40.5% for the secondary earner. This household pays about $14,000 in income tax per year, and is entitled to about $5,506 in tax credits.

• Including Labour’s proposed ‘Best Start’ entitles the same household to tax credits of about $7,500 per year.

• However, for the same household when the new born turns 1, tax credits would fall to about $4,470. The cost to the primary earner of earning an extra dollar would increase to 61.7%, while the cost to the secondary earner would increase to 49.2%.

Depending on their circumstances, some households will notice that their effective marginal tax rate may be high across the middle of the taxable income range.

“While this version of the NZTWC includes the tax credits listed above, our plan is to add further interpretive information, as well as more tax credits and welfare payments that households or individuals receive under the current system. If tax changes, or changes to tax credits, are announced in today’s Budget—as Prime Minister John Key signalled yesterday—we will look to include them.

We also plan to add policies that are announced by political parties in the run up to this September’s general election,” says Steve Thomas.

“Our hope is that the NZTWC will be a helpful tool to those wanting to assess how much better or worse off they would be under different parties’ policies. It could also be a helpful decision-making tool for those who want to think about how changing circumstances might affect their income,” says Thomas.

“Finally, we hope that the NZTWC can help those designing alternative welfare policies to see

the impact of their proposals, and assess the trade-offs that are made between providing income assistance and not unduly harming households’ livelihoods and work incentives.”


The NZTWC is provided for information and illustrative purposes. The NZTWC is not intended to be financial advice, nor should it be used in this way.

All reasonable care has been taken in preparing and designing the NZTWC; however, we provide no warranties and make no representation that the information provided by the NZTWC is appropriate for users’ particular circumstances or indicates that they should follow a particular course of action.


© Scoop Media

Business Headlines | Sci-Tech Headlines


Hourly Wage Gap Grows: Gender Pay Gap Still Fixed At Fourteen Percent

“The totally unchanged pay gap is a slap in the face for women, families and the economy,” says Coalition spokesperson, Angela McLeod. Even worse, Māori and Pacific women face an outrageous pay gap of 28% and 33% when compared with the pay packets of Pākehā men. More>>


Housing: English On Housing Affordability And The Economy

"Long lead times in the planning process tend to drive prices higher in the upswing of the housing cycle. And those lead times increase the risk that eight years later, when additional supply arrives, the demand shock that spurred the additional supply has reversed. The resulting excess supply could produce a price crash..." More>>


Sweet Health: Sugary Drinks Banned From Hospitals And Health Boards

All hospitals and DHBs are expected to kick sugary drinks out of their premises. University of Auckland researcher, Dr Gerhard Sundborn who also heads public health advocacy group “FIZZ”, says he welcomes the initiative. More>>


NASA: Evidence Of Liquid Water On Today's Mars

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. More>>


Bird Brains: Robins Can Just Be Generally Clever

Research from Victoria University of Wellington has revealed that birds may possess a ‘general intelligence’ similar to humans, with some individuals able to excel in multiple cognitive tests. More>>


Psa-V: Positive Result On Whangarei Kiwifruit Orchard

Kiwifruit Vine Health (KVH) has received a Psa-V positive test result on Hort16A and male vines on a kiwifruit orchard in Whangarei. This is the first confirmed case of Psa-V on an orchard in the Whangarei region. More>>

Regional Accents: Are Microbes The Key To Geographical Differences In Wine?

A new study of six of New Zealand’s major wine-growing regions has found that differences in flavour and aroma of wine from different areas may depend more on microbes than was previously thought. More>>


Science: AgResearch To Cut Science Staff In Areas Of 'Reduced Demand'

“We are therefore consulting with our staff from today on a proposal to reduce science staff in areas of shrinking demand. Combined with recruitment planned in areas of growing demand, this would mean a net reduction of 15 scientists and 41 technicians at AgResearch in the 2015/16 year." More>>


Get More From Scoop

Search Scoop  
Powered by Vodafone
NZ independent news