• Superannuitants' annual cost of living up 4.5%, low-income 4.3% 
  • Annual inflation rate 4.1% in June year
  • Big income earners annual rate 1.9%, average household 3.2%
  • Petrol price surge hits all groups, but many households benefit from falling interest rates

The cost of living has risen faster than inflation for superannuitants and low-income earners, according to new data from Stats NZ.

It calculated the living costs for 13 different demographic groups, including low-income households, beneficiaries, Māori and superannuitants, along with various income level groups.

Stats NZ prices spokesperson Nicola Growden said the 27.5% annual rise in the cost of petrol was the main reason for the rise in all household groups, although the impact affected various groups differently.

"Higher petrol prices accounted for almost one-third of the annual increase in living costs for the average household."

"The increase in petrol prices had the largest impact on lower-spending households, as petrol makes up a larger proportion of their expenditure."

She said higher diesel prices had much less impact because as a fuel it was not consumed by most households.

Low- and fixed-income wear the pain

Groups on fixed or low incomes such as superannuitants and students faced 4.5% and 4.3% rises in the living costs, respectively.

That compared with headline inflation for the year ended June of 4.1%, also on the back of the surge in fuel prices.

The average and Māori households faced a 3.2% increase, and beneficiaries 3.7 %, while high-spending households faced a 1.9% increase.

Growden said the significant difference was the fall in interest rates over the past year, which are included in household costs but not in the broader consumer price index (CPI), which instead contained the cost of building a new house.

"Interest payments for the average household fell more than 15% ... while the cost of building a new home increased 2.7%."

Other notable cost increases included in the broad inflation measure were electricity, rates, insurance and some food items.