"Without some sort of multi-party agreement, I don't see that we can have durable solutions," he said.
"The challenge is how can we get that degree of consensus around durable actions to reduce poverty. It might be an act, or it might be other cross-party specific measures in relation to forms of family assistance."
Professor Boston said New Zealand's child poverty rate - one in every five children - was in line with the OECD average of 20 per cent, based on the numbers in families with under 60 per cent of median income.
Another member of the group, economist Dr Bob Stephens, said that was nothing to be proud of.
"The fact that we are equal to the OECD and the European Union averages just means that every country is bloody awful.
"Okay, the Germans and Swedes and Dutch are better off, but even they are not particularly brilliant," he said.
New Zealand's poverty is concentrated in minority ethnic groups.
Ethnic breakdowns are not available for children, but the overall poverty rates in 2010 were around 10 per cent for Europeans, 20 per cent for Maori and 25 per cent for Pacific people.
Tongan-born Auckland University of Technology accounting lecturer Dr Semisi (James) Prescott, who is also on the expert group, said cutting child poverty would need action on all levels from legislation to local communities and individual families.
"For example, Pacific Island people need to recognise that early intervention is important - going to the doctor before it gets to a situation where it is so serious that you race off to a hospital," Dr Prescott said
A Maori member, Sharon Wilson-Davis of Mangere's Strive Community Trust, said targets were important but the top priority should be helping with basic skills such as budgeting for families who might never have known anything except life on a benefit.
