"What I see is the possibility that something gets initialled late May — I just don't know if they will make it — and at that stage it is all out on the table," he said. "Then the politics will get quite interesting because we can then pore over the text and the interest groups start coming in. Every country has to ratify one way or another, which would take a year.
"And that could be quite a busy, noisy year."
A sticking point has been Japanese reluctance to open market access in the "sacred" agricultural sectors — rice, wheat, beef, pork, sugar and dairy products. The recent visit to Japan by US President Barack Obama failed to deliver a major breakthrough on that front, though Bollard said he had not expected it to.
The recently concluded bilateral agreement between Japan and Australia is seen as unambitious in terms of agricultural market access.
Bollard said another question was whether, if the TPP negotiations arrived at a "mediocre" outcome, New Zealand and some other TPP partners keen on an ambitious, high quality agreement would sign up to it anyway. "I wouldn't know."
Yet another complication is the lack of "fast track" negotiating authority on the US side, where the Senate, which has to ratify the pact, agrees to vote it up or down and not seek to amend it.
Meanwhile, China, which chairs Apec this year and is not one of the TPP partners, is looking to breathe life into the notion of a Free Trade Area of the Asia-Pacific (FTAAP).
The concept of a region-wide trade and investment pact has been around for years and Apec leaders declared in 2010 that "now is the time for Apec to translate FTAAP from an aspirational to a more concrete vision".
Bollard said Apec leaders had all ritualistically repeated that since then but nothing had been done about it.
"The question of FTAAP is what is it? It has become a beacon out there but no one has had to define it."
The Taipei Times reported on Thursday Chinese Assistant Minister of Commerce Wang Shouwen as saying China proposed setting up a working group to study the feasibility of a FTAAP.
As well as TPP, whose members apart from Vietnam and Peru are all developed economies, there is the Regional Comprehensive Economic Partnership (RCEP) and the Pacific Alliance.
RCEP is an FTA negotiation among the 10 members of the Association of South-East Asian Nations (Asean) and the six countries, including New Zealand, with which Asean has existing FTAs. It has been described as "TPP with training wheels". The Pacific Alliance comprises Mexico, Peru and Chile, which are all Apec members, and Colombia, which is not.
"China would like to get all those on the table and work out how they all come together under this heading of FTAAP," Bollard said. "From our point of view we don't want to see these plurilateral agreements going off in different directions. And that is where Apec has its role to play as incubator and integrator — bright ideas and bringing things together."
