Controversial new data suggests that more than half of all sole parents on the domestic purposes benefit (DPB) first became beneficiaries as teenagers.

The figure is higher than the Ministry of Social Development's official estimate of a third, and implies that most people on the DPB have been long-term welfare beneficiaries even though many of them have had spells in paid work.

The finding means that the Government's review of the welfare state led by economist Paula Rebstock is even more challenging than had been thought because most teenagers who have babies early come from broken families, often with backgrounds of gangs, drugs, alcohol and abuse that cannot be solved simply by changing welfare rules.

However, the picture is confusing, with a range of apparently contradictory figures.

Only 3686 (3.3 per cent) of the 111,689 people on the DPB at the end of June were aged 18 or 19. The last available count for the emergency maintenance allowance (EMA) paid to young mothers aged 16 or 17, for June last year, was 1831.

But parents who go on the DPB before age 20 stay on it much longer, on average, than people who go on to it when their relationships break up in later life, so a much higher proportion of those now on the DPB started on it in their teens.

The ministry's official estimate that a third of DPB recipients started on it in their teens is based on comparing the parents' birth dates with the birth dates of all the children included in their benefits over 10 years.

But this estimate is not conclusive because the ministry only holds full information on the benefit history of all current beneficiaries since 1996 - effectively only for people who turned 16 in or after 1996, and who were therefore 29 or under by last year.

Responding to an Official Information Act request, ministry head Peter Hughes told economist Susan St John that 52 per cent of mothers on the DPB and aged 29 or under at the end of last year first received the DPB or EMA as teenagers.

Maori women were especially likely to start on the DPB or EMA as teenagers - 59 per cent of Maori mothers who were on the DPB and under age 29 last year started as teens, compared with 47 per cent for European women and 45 per cent for Pacific Island women.

A report issued today by Ms Rebstock's welfare working group shows that more than 40 per cent of all Maori women in their twenties were on welfare benefits at the last Census, mostly on the DPB.

In another set of data released to former Act Party candidate Lindsay Mitchell, Mr Hughes said that 86 per cent of all sole parents under age 29 who were on the DPB or EMA last September first received benefits of some kind as teenagers.

A spokeswoman said these figures could not necessarily be extrapolated to DPB recipients aged 30 or over, for which early benefit history is lacking.

"We expect that the proportion of DPB clients who first received any benefit as a teenager is somewhat higher than a third, particularly as receipt of a benefit is such a common experience in people's teenage years.

"But again, the proportion cannot be estimated because of the limited time period over which we can look back and observe benefit receipt in people's teenage years."