A 17% rise in child poverty revealed in this year's child poverty report has perplexed child health researchers and is likely to reignite the income inequality debate.
Produced by the University of Otago's child and youth epidemiology service, the Child Poverty Monitor, released today, shows 305,000 New Zealand children are living in poverty, compared with 260,000 in 2013.
The most recent data in the report is from 2014.
"There has been a significant increase in income poverty for children.
"It is difficult to pinpoint why this is or whether it is a trend that will continue,'' the researchers said.
All up, 29% of New Zealand children live in poverty, defined as the proportion in households earning less than 60% of the median income, after housing costs.
A lift in the median income partly explains the increase, meaning some families' fortunes have improved, but others are stagnating.
"A small increase in the threshold means many families that had been just above the measure last year are now counted as being in poverty.''
While the most dramatic rise was seen in the growing gap between families, the poverty increase also showed up in the other measures.
"This does suggest that inequalities are rising - with households at the poorer end of the income scale doing [increasingly] worse than middle and high income households,'' the researchers said.
The report examines complex data to determine whether the wellbeing of children is improving or worsening.
One measure is hospital admissions for conditions that are linked with socioeconomic status, which rose from 37.6% of children to 45.7% in the past 14 years, but has been relatively stable since 2009.
The report also looks at big picture economics, highlighting New Zealand's lagging wage growth. While per person gross domestic product increased 60% between 1975 and 2015 (in 2013-14 dollars), wages grew by just 23%.
Now in its third year, the monitor is a joint project between the Children's Commissioner, the J R McKenzie Trust and the child and youth epidemiology service.
Children's Commissioner Dr Russell Wills said no matter how poverty was measured, it was clear life was tougher than 30 years ago.
"When almost one in 10 of our children are at the very hardest end of poverty, it tells us we've got a long way to go.''
Dr Wills is spearheading a social media campaign with the slogan #itsnotchoice, and in a statement yesterday encouraged people to take part in a "selfie'' campaign to fight child poverty.
Child and youth epidemiology service director Dr Jean Simpson said negative health outcomes associated with child poverty were starkly apparent in the rates of hospital admissions for infectious and respiratory diseases.
"These ... are related to living conditions. Being in damp, cold houses where there is overcrowding is bad for children's health.''
The median income is the mid-point: half will have more and half less.
It is not average income.
Child poverty
• 29% of children live in income poverty, compared with 24% the previous year.
• About 14% (148,000) live in material hardship
• Child poverty rate nearly double that of 1985.
• About 16% of children live in a crowded house.
• More than a third of children live in households that spend more than 30% of their income on housing.
• Almost 17% of children reliant on benefit recipients.
• Children are two and a-half times more likely to be in poverty than those aged 65 and over.
• About 33% of Maori and 28% of Pacific children live in poor households, compared with 16% of European children.
Source: Child Poverty Monitor
