'Concerted effort'

Overall, the rate of unanimous judgments rose from 35 per cent in 2017 to 44 per cent in 2018. Justice Kiefel, who assumed the top job in January 2017, has indicted the increase is no accident.

"There has been a concerted effort to find common ground and reduce the number of individual judgments where justices are largely in agreement," she said in a speech at Oxford University.

She added there was a "clear willingness on the part of the justices to participate in more extensive discussion than before and to work through difficult questions together".

Professor Lynch said the court's decisions bear out the Chief Justice's public remarks.

"The High Court's 2018 decisions show the continuing emphasis under the leadership of Chief Justice Kiefel on the benefits of the court explaining its decisions through joint judgments rather than a series of individual opinions.

"In particular, the frequency of joining between Chief Justice Kiefel and Justices Bell and Keane represents a solid core of decision-making on the bench.


"These judges were integral to the institutional voice of the court in 2018.

"Consistent with that, these Justices dissented only once each last year – and even then, Kiefel and Keane did so by writing together."

The accompanying table shows the Chief Justice wrote with both Justice Bell and Justice Keane in 64 per cent of her 50 decisions. Justice Bell wrote with Chief Justice Kiefel in 84 per cent of her 38 cases and Justice Keane wrote with the Chief Justice in 80 per cent of the 40 cases he decided.

Most dissents

Professor Lynch added that Justice Bell and Justice Keane "did not join quite as often with each other as they did with the Chief Justice, but they did so ahead of any other members of the court".

Justice Geoffrey Nettle delivered the most dissents (five) in a year in which all members of the court took a contrary view to the majority at least once – the first time this had happened since 2013.

There were 13 cases from Nauru in 2018, the last year the court took appeals from the tiny Pacific island under a 40-year-old treaty. All were refugee claims involving just three judges, with 11 decided unanimously.

The busiest judge was the Chief Justice, who sat on 50 of the 59 cases. She was was followed by Justices Stephen Gageler (47), Nettle (46), James Edelman (43), Michelle Gordon (41), Keane (40) and Bell (38).