Almost 95 per cent of all Year 1 primary school students in the year to last June had previously attended some kind of preschool education. But the proportion ranged from 99 per cent for schools in the richest tenth of the country down to 81.8 per cent of the poorest tenth.
Ethnically, previous preschool attendance ranged from 98.2 per cent for European children and 96.3 per cent for Asians down to 90 per cent for Maori and 85.9 per cent for Pacific children.
The Education Ministry plans to call tenders later this year for an $18 million information system that will give all preschool pupils identification numbers and track their attendancein all kinds of education and childcare.
Dr Wills said the new system should be used to trigger action when any child stopped attending.
"If a child is enrolled with a service, I think that should carry an obligation to engage with that child's family and some accountability for it."
NZ Kindergartens chief executive Clare Wells welcomed the proposal, saying kindergartens already followed up families to resolve any issues which stopped children attending.
Playcentre Federation co-president Maureen Woodhams said she could also see "lots of benefits" in the plan. Playcentres were initially wary of the new information system because many do not have computers on site, but Mrs Woodhams said they were working with the ministry to input their data from home computers or by phone.
But Early Childhood Council chief executive Peter Reynolds said his members were mostly private businesses and had "no capability or resources to enable such tracking to occur".
"It's not their role to do that," he said. "That is the role of the Ministry of Education, or Child, Youth and Family where they are involved."
Childcare Association chief executive Nancy Bell said her members would be willing to follow up families when a child left, and were already contracted by the ministry to "knock on doors" to find unenrolled children in South Auckland.
Ministry of Education early childhood manager Karl Le Quesne said officials were looking at whether the new information system could be integrated with health information, possibly by data-matching, to help track children not enrolled in preschool services.
Decisions are expected in time to seek tenders this year, design and build the system next year and implement it in 2014.