"It may be that very structured investment, if spent differently, could make more of a difference to health and education outcomes than it currently does."
Dr Wills said elderly people would be willing to see more targeted pensions if the savings went to needy children.
He also nominated Working for Families as a programme that was "not as targeted as you think".
A family with four children can get abated tax credits on incomes of up to $120,000 a year.
His comments go far beyond anything that is likely to be in the Budget, but are based on what ministers have said about limited cash for new programmes.
A report last week said 74 per cent of beneficiaries under age 25 came from intergenerational welfare families where their parents were also on benefits.
The report recommended giving priority to parents with children for intensive case management to break that cycle.
Victoria University's Professor Jonathan Boston, who co-led an expert group on child poverty for Dr Wills in 2012, said the Budget might "tweak" family tax credits to give more to young children and less to older children, or the accommodation supplement to give more help to larger families.
But Auckland University economist Dr Susan St John said free healthcare for children under 13, due to start on July 1, was appropriate "targeting on to sick children".
