Not that long ago, Australians owned many public enterprises and lived behind high tariff walls. The country ran on cheap coal-fired power. A pro-China foreign policy and a large, bipartisan migration program worked to the country’s benefit.

Today’s policy landscape would have been unimaginable to many voters 40 years ago. Most of the old state-owned enterprises now belong to shareholders. National Party leader Matt Canavan is a very lonely voice in his calls for renewed tariff protectionism.

In the face of global heating, Australia continues to experience social division over the future of its energy generation. The nation’s flagship defence policy to tackle regional uncertainty involves closer ties with old Anglosphere allies. And politicians of every hue are tying themselves in knots in a quest to lower net overseas migration.

How do policy cycles come to be, and what causes them to be remade over time? There’s a concept that could help us answer these questions: the Overton window.

To borrow a concise definition from foreign policy expert Thomas Wright, the Overton window is the idea that there is an “acceptable range of political discourse in a society” at a given time. For example, it was once crazy-brave to argue for the end of the White Australia policy – until it wasn’t.

In democratic systems, leaders and parties tend to stick within these boundaries to remain popular and legitimate.

The concept takes its name from the late Joseph Overton, an electrical engineer and senior figure at the influential Mackinac Center for Public Policy in Michigan.

His colleague Joseph G. Lehman recently blogged that Overton’s concept was intended to “describe what think tanks do and explain why someone might support one”.

Think tanks are research and advocacy organisations. Some are staunchly independent while others are explicitly connected with or aligned to a partisan cause. An instinctive libertarian, Overton thought think tanks could stretch the limits of political possibility where risk-averse, vote-chasing politicians never could.

Overton died in 2003, with no inkling his name would be associated with one of the most widely used political terms of our times. It has become a standard phrase among policy wonks and especially in think tanks (including progressive organisations whose politics Overton would have staunchly opposed).

Shifting windows, shifting climate

The Overton window seems convenient for explaining big shifts in public policy. But just how good is it?

Could it, for example, help us understand something as messy as Australia’s........

© The Conversation