Grattan on Friday: Amid the warm glow, we don't yet know Malcolm Turnbull's program

When Malcolm Turnbull boarded a Melbourne tram on Thursday for a newspaper photograph, a cheer went up from passengers. The man seems to have slid into the prime ministership as though he were made for it. As he thinks he was, of course.

Some of this easy public transition is because of Tony Abbott. The former prime minister and his administration had become so unpopular that there was just relief, on multiple fronts, when the Turnbull coup happened.

Turnbull has told us what his government believes in philosophically (freedom, the free market) and what he has learnt from his earlier failed leadership stint (he’s “wiser about people”).

In early policy, welcome measures and money have been announced to help tackle the scourge of domestic violence. The package had been in the pipeline for Abbott and inherited by Turnbull.

Amid the warm glow, and that sunny smile of the new prime minister, it’s worth remembering one thing. This will be a government of surprises, good or otherwise. The point is, we don’t yet know the Turnbull program.

When a leader wins an election, he or she arrives with a set of commitments – although they may turn out an unreliable guide, as we learned in 2014. Turnbull’s pre-coup public pitch was about what was wrong with Abbott, not future directions, and because he had been a senior minister rather than launching a challenge from the backbench, he hadn’t laid out a manifesto.

We have watched Turnbull for years so we think we know him. But the prime ministerial beast can turn out quite different in nature from the aspirant. The performances of the last three prime ministers were worse than expected; John Howard exceeded expectations.

We did know for sure some Turnbull’s positions. He thought a market mechanism best to address climate change. He considered gay marriage should be handled by a free vote in parliament.

But these stands were put aside even before he became prime minister, in order to muster party votes. So we have learnt that pragmatism runs deep in this leader, and can be overriding.

That, however, does not provide a map of his government’s likely paths. It does not tell us with any precision to what extent he will follow his moderate instincts, or temper them to keep conservative support. And for that matter, it’s hard to predict whether his “consultative” approach will see him do more wrangling or nuancing. His political persona is complex.

Turnbull is committed to tax reform, but what will that mean in practice?

To be fair, where Abbott and Joe Hockey would have landed on tax changes is a forever known unknown - their messages were all over the place.

We do know what they would not have done – Abbott ruled out touching superannuation or negative gearing. The Turnbull government is unwilling to play the rule-in-rule-out game. How long that lasts remains to be seen. There will be a temptation, if not a political imperative, at some point to start ruling things out before next year’s white paper.

In coming months much will ride on the new Treasurer. Scott Morrison likes slogans – his latest is “work, save, invest”. “If something is going to help people work, save and invest through a change in the tax system, then I’m interested in it,” he said on Wednesday.

Morrison wants to focus discussion on the benefits of tax reform – how it will help families and businesses. Until the voters have the details, however, it will be all rather airy-fairy.

Morrison is already under criticism for his black-is-white claim we have a spending problem, not a revenue problem. This goes against expert opinion, including that of respected former treasury head Ken Henry, who this week said the tax package needs to be revenue positive.

The government wants its tax revamp, while not increasing the overall tax burden, to produce a system which helps drive economic growth, which is good for revenue longer term. But if it sees restraining spending as paramount in fiscal consolidation, that would imply severe cuts. How is this possible with an election looming in a year? Maybe the budget emergency will continue to be – well, not such an emergency.

Equally unknown territory is where Abbott’s review of the federation will go under Turnbull.

Abbott seemed inclined to push more functions down to state level. Turnbull has just appointed a minister for cities and the built environment. This implies the federal government taking an active approach on issues that are in the states' domain. And he is as committed to public transport as to roads, which will mean a changed attitude to funding.

Industrial relations is another reform area where the new prime minister is yet to reveal his hand. Here he will be under pressure from business, whose demands will exceed what the electorate would bear.

Then there is higher education, which saw one of the Abbott government’s early, controversial and unsuccessful initiatives. Its plan to deregulate university fees has failed to pass the Senate. Turnbull and new Education Minister Simon Birmingham are signalling some walking away.

Turnbull can’t afford to rush to satisfy the media cycle and get things wrong; on the other hand, time is short. For any new prime minister, the first 100 days are important for the imprint they stamp. Turnbull needs to set directions early. Equally he has to forge an election platform over coming months.

Ideally, much of the Coalition’s reform agenda would have been out by now. But at least its absence provides Turnbull with maximum flexibility.

And that will suit the taste of this man who likes to say that “you need to be on the balls of your feet, always ready to take advantage of opportunities.”

Listen to the latest Politics with Michelle Grattan podcast with guest, Shadow Higher Education Minister Kim Carr.

Michelle Grattan does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.