"Currently there is a minimum English level required from all principal applicants, but higher levels are not rewarded," he said.
"Such rewards should be introduced, as evidence from New Zealand and from other OECD countries clearly shows that better proficiency of the host-country language is associated with better labour market outcomes."
The report also suggests reviving a requirement for applicants' family members to pay a bond if they could not pass the English test, which would be repaid once they passed the test.
New Zealand scrapped a bond system in 1998 and instead requires family members to pay for English tuition in advance. But the report says a third of immigrants who pay for tuition in advance never attend their courses. It says the prospect of getting their bond back would give them stronger incentives to learn English.
It warns the numbers of young foreigners on working holidays or studying in New Zealand are reaching levels that may worsen local youth unemployment.
Temporary workers under working-holiday schemes for people aged 18 to 29 have leapt from below 10,000 a year in the 1990s to 50,000 and represent 8 per cent of New Zealanders in the same age group.
On top of that, there are about 100,000 overseas students — 60 per cent are in Auckland and about three-quarters with visas allowing them to work up to 20 hours a week. The report says overseas students with work rights represent 6 per cent of NZ youth aged 15 to 24, and 11 per cent in Auckland. Most overseas students work in hotels, restaurants and retailing, which are also the biggest employers of low-skilled NZ youth.
The report recommends investigating the effects of both working holidays and overseas students on NZ youth employment and tightening controls on their working conditions.
Immigration Minister Michael Woodhouse said the report's English language proposals would be considered as part of a planned review of the skilled migrant category.
Labour immigration spokesman Trevor Mallard said Labour would "tighten up on the quality and the level of courses where [students] are able to work".
Migration and Investment Association chairwoman June Ranson said the minimum English language requirement was "between a good and competent user of the English language" and extra points for higher-level English would not add anything useful.
Achieving well
• Migrants in jobs.
• Migrants in jobs aligned to their qualifications.
Could do better
• Award points for high-level English.
• Require bond for family members to learn English.
• Tighten watch on working-holiday permits and working overseas students.