Election date speculation has long been one of the favourite pastimes of Australia's political pundits, but Opposition Leader Bill Shorten wants that to become a thing of the past.

Yesterday, he told ABC's Insiders we should have fixed four-year parliamentary terms. And it looks like Malcolm Turnbull could be open to the idea, with the Prime Minister calling Mr Shorten afterwards and agreeing to discuss the issue next time the two leaders meet (although Treasurer Scott Morrison has since clarified it's "not a priority").

Here's what fixed-term elections could mean for Australia.

What are fixed-term elections?

Basically, they mean the prime minister or premier of the day doesn't get to decide when to have an election — the date is already set in advance.

For instance, in Victoria, the state election is held every four years on the last Saturday in November. In New South Wales, it's the fourth Saturday in March.

The only states which don't already have fixed terms are Tasmania and Queensland (where they'll be introduced after the next Queensland election).

Under the current federal system, the prime minister can go to an election at any time, as long as parliament doesn't run for more than three years.

What other countries have them?

Many other Western nations have fixed-term elections, including the United States, Britain and Canada, as well as most countries in continental Europe.

As an aside, Australia is unusual in having three-year terms — the majority of countries have four- or five-year terms.

Why would we want four-year fixed terms?

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 14 minutes 55 seconds 14 m Barrie Cassidy interviews Opposition Leader Bill Shorten

Mr Shorten told the ABC the current system was stifling reform.

"The average life of a federal government is two-and-a-half years — not even three years," he said.

"Governments can be more daring and determined if they're not constantly thinking about the next election. If prime ministers of the day don't have the tempting trigger to pull that if they have an improvement in their short-term position they'll race to the polls."

These are said to be some of the other advantages of four-year fixed terms:

they provide certainty to business

they provide certainty to business they reduce the frequency and cost of elections

they reduce the frequency and cost of elections they remove the ability of prime ministers to call early elections for political reasons

Why wouldn't we want them?

One of the main arguments against fixed terms is that this stops the prime minister from "going to the people" when they deem this necessary, which is seen by some as an essential feature of Westminster democracy.

For instance, a government might be getting frustrated by an obstructionist opposition; or they might want to seek the public's support for a new policy; or a prime minister installed mid-term might want a fresh mandate.

Some fixed-term systems do allow for early elections under extraordinary circumstances. For instance, with the support of Jeremy Corbyn's Opposition, British PM Theresa May was able to call an early election in order to get a mandate on Brexit.

These are some of the other potential disadvantages of fixed terms:

they are less democratic because voters have to wait longer before they can express their disapproval

they are less democratic because voters have to wait longer before they can express their disapproval they can lead to ineffective governments being in power for longer

they can lead to ineffective governments being in power for longer they lead to longer (and thus more expensive) election campaigns

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 7 minutes 10 seconds 7 m Constitutional law expert George Williams talks about Bill Shorten's proposal

Is this going to happen anytime soon?

"I can't see it happening within a decade," ABC elections analyst Antony Green said.

For starters, it would require a referendum for the Lower House to go from three- to four-year terms. And that's just the start of the complications, because you'd also need to figure out how double dissolutions would work as well as what to do about Senate terms — would they be shortened to four years or lengthened to eight?

However, these problems would go away with three-year fixed terms, which could be enacted without a referendum.

This is the model supported by Ben Oquist, executive director of The Australia Institute, who said it would be "good for democracy".

"It would stop the prime minister being able to pick and choose election dates and manipulate election timing," he said.

"It would be better for governing and we wouldn't waste so much about when an election is going to be."