Illustration: Andrew Dyson.

Illustration: Andrew Dyson.

This time next week, Tony Abbott will be prime minister, probably with a majority of more than 30 seats. For his supporters, it will feel like a return to normal after the chaos and disappointments of the Labor years. It will seem like the Howard government is back.

They might be so lucky; sometimes the Liberals are. But the years ahead are unlikely to resemble the Howard years. The challenges are very different. The world will be far less supportive. Our economy needs new drivers of growth, our budget needs new revenues. Abbott is not John Howard. And he could find himself facing a very difficult Senate.

Abbott has dominated over Labor due to negative campaigns, especially his scare campaign against the carbon tax, which was more successful than it deserved to be.

Inflation in year one of the tax was just 2.4 per cent, and the data showing the past year was the hottest on record in Australia underlines why Labor, like John Howard, decided that a price on carbon was the cheapest way to insure against the risks of global warming.

Now Abbott will have to govern, which takes different skills. The difficulties he has exploited against Labor will become his to manage. And he has promised that his will be ''a no-surprises, no-excuses government''.

First, the world. We look back on the Howard era as years of prosperity, and they were. But, in part, we prospered because global growth averaged 4 per cent a year. The Rudd/Gillard years have been more difficult, in part because global growth slumped to an average of 2.9 per cent a year.

In Howard's last six years, global output grew 30 per cent. In Labor's six years, it has grown 19 per cent. That makes a difference to what the government and the economy can do.

The world economy now seems to be shifting gears. The outlook for Europe and the US is improving: the eurozone recorded its first growth for almost two years in the June quarter, and unemployment fell marginally in July. The US recovery has gathered enough strength and resilience to almost persuade the Fed to start cutting back the credit creation it used to get the recovery going.

But, at the same time, the outlook has worsened for China, India, Indonesia, and the developing world. The markets are looking more carefully at the rising debt that has underpinned their rapid growth, and are troubled. The world is not becoming riskier, but the risks are shifting closer to us.

Second, Australia's economy is leaping from one phase of growth to another, with no certainty that it will grab the trapeze bar. Last week's capital expenditure figures suggested that the mining investment boom is receding slowly, rather than being in free fall. But fall it will, and as Reserve Bank governor Glenn Stevens put it recently, ''it could be quite a big fall in due course''.

Third, the budget is stuck in deficit because of deep problems that will not change just because the government changes. Revenue in the Howard government's last six years was 25.4 per cent of GDP; in Labor's six years it has been 22.7 per cent, and on Treasury's projections, it will not return to Howard-era levels for years. And 2.7 per cent of GDP is $43 billion a year.

Abbott was lucky that Kevin Rudd last week threw away his best campaign weapon by claiming Treasury and Department of Finance support for his attack on the Coalition's costings. The Coalition has published no detailed costings of any policy, and won't do so. We will not get the detail of its spending cuts until a month after the election, when the Parliamentary Budget Office publishes its costings.

It's a successful political strategy to ensure voters focus on Labor's record, rather than on the Coalition's alternative. But it is very disappointing from the party that gave us the Charter of Budget Honesty. It is not a good sign for the future.

Fourth, the Senate will remain outside the Coalition's control, and could reject much of its legislation. The proliferation of microparties swapping preferences tightly could cost the Coalition Senate seats in one or more of Victoria, NSW and Queensland - and in NSW, the senator at risk is the widely respected Arthur Sinodinos, who would be finance minister if he wins.

Until mid-2014, the Senate will remain under the control of Labor and the Greens. Control could then pass to a mix of the Greens and small parties of the right. They might vote with the Coalition to repeal the carbon price, but if Labor holds firm, that is no certainty. But it's not hard to see them blocking the Coalition's plans to scrap the government contribution to low-income earners' superannuation, or to cut $1 billion a year from tax breaks for small business.

Abbott will face the same problems in the Senate that Labor faced in the House. And while he has the option of a double dissolution, that is a high-risk strategy, because then the threshold for a Senate seat drops from 14.3 per cent to just 7.7 per cent after preferences; the Coalition could lose seats to microparties of the right, and come back worse off.

Finally, it is not clear what the Coalition's plans are, apart from ending the carbon tax and mining tax and stopping the boats. We know that new Coalition governments always tell us the budget is in worse shape than Labor said, and that they will have to make cuts they did not announce in the campaign so we can get back to surplus. In this case it might be true, particularly if Joe Hockey takes the sensible step of telling Treasury to use forecasts rather than projections for growth beyond the next two years.

We know that Hockey will order a Commission of Audit, which will recommend more spending cuts. They will establish a Productivity Commission inquiry into workplace relations that will propose changes that go well beyond Abbott's official policy. The commission's inquiry into the car industry will recommend an end to industry support. We know all that, because that's what they always do.

The car industry is a classic example of why government is so difficult; only subsidies can keep it going, yet take them away, and you lose the whole industry. One reason Labor had so much trouble governing is that the problems are so tough, and it did not control the Parliament.

From Monday, these will be Tony Abbott's problems. Wish him luck.

Tim Colebatch is economics editor of The Age.