However, Ms Black believes the widening gap between the poor and the relatively better off revealed in the Child Poverty Monitor is not happening in Dunedin, which has a flat economy in which no group appeared to be better off.
The number of children in poverty shot up by 17% in a single year, partly because median wage growth meant more families fell under the poverty line.
Ms Black said fewer and fewer people now benefited from a rising economy.
Dunedin had a "substantial number'' of struggling families, and many people did not understand it included those with two working parents.
"This is a country where you're supposed to be able to get up, work hard, and do OK [financially].''
Children's Commissioner Dr Russell Wills has called for change in the wake of the report, which shows poverty has nearly doubled since 1985.
The report drew attention to New Zealand's poor wage growth, and the Otago Daily Times asked two economists why workers' share of the economy had fallen in recent decades.
New Zealand Initiative head of research Dr Eric Crampton said the report focused on relative poverty, which masked wage rises.
"If we look at the proportions of children below fixed poverty thresholds, rather than the relative income measures highlighted in the report, the proportion of children in poverty dropped from 18% in 1982, to 10% in 2014, if we measure things before housing costs,'' Dr Crampton said.
The big problem was the cost of housing, not lack of income.
"Because we have made it very difficult to build new housing, through very constraining zoning rules, we have made housing very expensive.
"And the costs of that fall most heavily on the poor, and particularly on poor children in overcrowded, poor-quality housing.''
He acknowledged workers received a smaller share, but that was because growth had come from investment in plant and equipment rather than labour productivity.
However, Council of Trade Unions economist Dr Bill Rosenberg said the main problem was workers' loss of bargaining power.
Workers in other countries were also affected by technology change but New Zealand was hit with a "perfect storm''.
"The de-unionisation that happened with the Employment Contracts Act in the early 1990s took away bargaining power from working people and gave it to employers in a really big way.''
Dr Rosenberg said he was surprised by the report, as he had not realised inequality was getting worse.
Economists are unlikely to ever settle the matter, but Presbyterian Support Otago chief executive Gillian Bremner said affected children had no say in their circumstances, and the problem needed to be sorted.
"I think we have to acknowledge that the current support that's provided is inadequate.
"The Child Poverty Action Group has provided sufficient ways forward in what should be done to make a difference.
"There is a degree to which we choose to turn away and not notice, not want to notice.''
