We've had income tax for 100 years and we are still arguing.
A two-day conference at ANU next week will mark the nation's other centenary and one of the most significant economic reforms in Australia's history.
The year 2015 marks the 100th anniversary of federal income tax.
The income tax was introduced to fund Australia's involvement in World War One and to support the newly-established national age pension, which is the cornerstone of Australia's social security system.
"We've had income tax for 100 years and we are still arguing, as we should in a vibrant democracy, about tax rates and what it pays for," said Professor Miranda Stewart, Director of the ANU Tax and Transfer Policy Institute (TTPI) at the Crawford School of Public Policy.
"The big question now is what shape we want Australia's income tax system to take over the next 100 years."
Professor Stewart will host the two-day event with experts from the United States and around Australia, including speakers from Treasury, the Australian Tax Office, government and opposition, at the Crawford School of Public Policy at ANU on Monday 27 April and Tuesday 28 April.
Media are invited to attend the conference, Looking Forward at 100 years: Where Next for the Income Tax. The program available via the link.
Since World War Two, income taxes have raised more than 40 per cent of total Australian revenues and Australia has a higher reliance on income tax for government revenue than most other developed economies, apart from New Zealand and Canada.
"Income tax will always be part of the tax mix," Professor Stewart said.
"The question is how to make sure it is responsive to new ways of working and investing in a global digital economy."
Professor Stewart said Australia needed to address problems with the tax and government payments system, which can discourage people, particularly part-time workers and women who have left work to care for children, from re-entering the workforce or increasing work hours.
"Australia's personal income tax and transfer system is increasingly complex and has gaps that reduce its effectiveness while imposing burdens on the economy," she said.
"If we remove some gaps and concessions, especially uneven treatment of savings and investment, this could allow lower tax rates for most workers while keeping a progressive tax system for the top 10 percent of income earners."
The conference will also look at the role of income taxes in our federation and the future of the company tax and small business income taxation.
The conference comes as the government considers options on tax reform for its Tax White Paper before the next election.
The conference follows the release in March of the TPPI's comprehensive stocktake of the Australian tax system and changes in the five years since the Henry Tax Review. Copies of the report are available at http://bit.ly/TTPIstocktake.