The Australian and New Zealand Productivity Commissions recommend waiving rules of origin requirements for transtasman goods trade.
It is one of the initiatives recommended in a scoping study undertaken for the two governments on how to strengthen economic relations between New Zealand and Australia.
To qualify for tariff-free entry under Closer Economic Relations, exporters must show that enough of the value of the goods originated in New Zealand or Australia as the case may be.
The commissions recommend scrapping the requirement for goods for which tariffs (on third parties) are 5 per cent or less, the great majority, and bringing remaining higher tariffs down to that level by, say, 2015. They also recommend scrapping the exemption international shipping lines enjoy from competition law prohibitions on restrictive trade practices.
Some issues, however, are kicked into touch in the draft report released today.
The vexed and longstanding issue of the double taxation of transtasman investment is put in the "requires further investigation" pile.
Mutual recognition of imputation or franking credits would cost both governments money, Australia more than New Zealand, but could expand investment and bring efficiency gains.
On the movement of people between the two countries, which has resulted in almost 500,000 New Zealanders living in Australia, the commissions note concerns about the possible hollowing out of the New Zealand workforce.
Whether New Zealanders who have lived and worked in Australia for an extended period have appropriate access to social security entitlements and pathways to citizenship is deemed to need further study, as are potential future costs for the New Zealand Government arising from New Zealanders returning to collect a more generous taxpayer-funded pension, especially if the age of eligibility is not raised.
The commissions also note estimates that up to $16 billion has been accumulated under Australia's compulsory superannuation scheme by New Zealanders who have since returned to this country.
The two governments have agreed to legislate to allow portability of retirement savings. Canberra has yet to follow through. The commissions urge it to do so.
In all, 20 initiatives are proposed by the commissions.
Most are business-as-usual within the context of a mature relationship - CER is 30 years old next year - guided by regular ministerial meetings and the annual Australia-New Zealand leadership forum.
They includes pressing ahead with the SmartGate system for speeding flows through airports, scoping a common transtasman tourist visa which might encourage foreigners to visit both countries on a trip, and continuing to develop common systems for biosecurity.
One issue considered but rejected is monetary union.
While it would have benefits, in order to work it would require fiscal arrangements to cope with asymmetrical shocks - jargon for flows of tax dollars to offset blows that hammer one economy but not, or more than, the other.
"There are few instances where monetary union has worked effectively without some degree of political union."
Public feedback is being sought on the discussion draft. A final report will be presented to the two governments in early December.
7.5 - how many times bigger the Australian economy is than New Zealand's
5 - how many times larger Australia's population is.