Swan's budget strategy broadly right:Bowen Federal Treasurer Chris Bowen is sticking to the budget surplus timetable of his predecessor, earning Australia another tick of approval by a global ratings agency. In his first major address as treasurer, Mr Bowen said the budget settings announced by Wayne Swan in May were broadly right - a return to budget balance in 2015/16 and to surplus in 2016/17. "It is the right strategy, I think it is justified in economic terms to stick to the plan of returning to balance and then surplus," Mr Bowen told the National Press Club in Canberra on Thursday. If we were to rush to surplus now it would be a hammer blow to growth ... it would be a terrible strike to the Australian economy. Shadow treasurer Joe Hockey called on the government to open its books and expose its "incompetent decision-making." "They can have all the speeches and spins and appearances at the National Press Club that they want ... show us the real numbers that you've been briefed on the state of the budget," he told Sky News. Mr Bowen's speech coincided with credit agency Standard & Poor's announcing it was maintaining a top-line triple-A rating on Australia, with a stable outlook. The ranking reflects the nation's "significant fiscal and monetary policy flexibility, economic resilience, and public policy stability," S&P's credit analyst Craig Michaels said. However, Mr Bowen warned Australia was at an economic crossroads, with the end of the China resources investment boom set to deliver more volatility in prices of key commodity exports and Australia's terms of trade. "This is not a crisis, but it is a challenge," he insisted. The decrease in the terms of trade over the past two years has negatively impacted government revenues, despite the cushion provided by a depreciating Australian dollar. Mr Bowen also said that while the waning of the domestic resource investment boom would detract from growth, that did not mean the economy would "fall off a cliff." "Our challenge is in improving our productivity and competitiveness to assist in this transition," he said. This is the key economic challenge for the next three years. Treasury forecasts domestic gross domestic product (GDP) to grow at or slightly below trend growth of three per cent over the next three years, and to exceed that of other advanced economies. Mr Bowen also said Labor's plan to move from a fixed carbon price to an emissions trading scheme a year early would give non-mining parts of the economy a competitive boost. But he ruled out making any changes to the controversial minerals resource rent tax on the super profits of iron ore and coal producers, which is yet to deliver on its revenue forecasts.