Prime Minister Julia Gillard. Credit:Alex Ellinghausen Keating's iconoclastic contribution dismissed Labor's World War II leader John Curtin as a merely a ''trier'' and described Curtin's successor and fellow ALP hero Ben Chifley as a ''plodder''. In the wake of Keating's address, there were some fitful exchanges on the topic of prime ministerial achievement and whether Curtin deserved to be regarded as a great leader, but only ever a slow-burning discussion that petered out. For more than half a century, one method for analysing and debating presidential achievement in the US has been expert ratings; that is, polls of political historians and political scientists who are asked to rank the presidents. Needless to say, these are fallible exercises. It is difficult to draw a meaningful line between office holders who served in different eras and circumstances. Arriving at an overall rating of a leader's performance is problematic when their record encompasses (as it invariably does) both achievement and failure. Yet, despite such imperfections, rankings have become a hardy perennial in America and have stimulated discussion about the qualities valued in national leadership. While Australia has lagged far behind in its experience of leadership rankings, there have been several scattered experiments during the past two decades. Most were initiated by broadsheet newspapers, but a large prime ministerial ratings survey was organised out of the politics department at Monash University in 2010. Like its forerunners, this exercise encountered scepticism, but about 40 surveys were completed by leading historians and political scientists.

Alfred Deakin. Read in conjunction with the results of earlier rankings, the Monash survey suggests there is a reasonable consensus about which leaders belong in the top echelon of Australian prime ministers. They are Liberal Protectionist Alfred Deakin, the three-time prime minister and chief architect of the nation-building edifice laid down in the first Commonwealth decade (including tariff protection, an industrial arbitration system, a basic wage and the beginnings of a welfare state in provision of age pensions); Curtin and Chifley, with the former recognised for his wartime leadership and as a collaborator with the latter in the design of the postwar reconstruction Keynesian-welfare state and its core principles of a managed economy and full employment; Robert Menzies, ''father'' of the modern Liberal Party and Australia's longest-serving national leader who won seven consecutive elections between 1949 and his retirement in 1966 - popularly remembered as an era of economic buoyancy and social stability; and Bob Hawke, whose Labor government modernised and internationalised Australia's economy in the 1980s through market-based reforms cushioned by an overlay of social democratic values. Strikingly, with the exception of Menzies, whose tenure is usually associated with a period of policy consolidation rather than major innovation, a feature of the record of each of these leaders is that they were regime builders: they initiated new and enduring macro-policy settlements. They were also political stayers and, apart from Hawke, endured serious parliamentary setbacks on their path to prime ministerial success. Most notably, Menzies weathered an unhappy minority prime ministership (1939-41) that ended in humiliating resignation. Robert Menzies. On the other hand, the rankings suggest that longevity in office and electoral popularity is not an automatic passport to a high standing: Joseph Lyons and Malcolm Fraser each won three elections and were in office for seven years apiece but neither rates very well.

Other qualities that distinguished the top-ranked prime ministers are that they were gifted communicators (arguably less so in Chifley's case), skilled expositors of the national image and possessed a vision of Australia's place in the world. They were men of integrity, but not without fallibilities. Curtin and, to a lesser degree, Hawke, had to overcome inner demons, and in particular a weakness for alcohol to succeed in office. John Curtin. According to the rankings, those prime ministers near to, but not making, the top tier are Labor's Andrew Fisher, leader of the first majority government in Australia whose governments consolidated and expanded Deakin's nation-building project; Gough Whitlam, the ALP moderniser, reforming titan and prime ministerial shooting star; and Paul Keating and John Howard, the two fierce rivals of the 1990s. Whitlam is an example of a leader who defies easy categorisation: lauded for his vision but marked down for faulty implementation in office. Keating's ranking raises the question of whether the experts struggle to separate out his partnership with Hawke in the 1980s from his own record in office. Some will think Howard's rating grudging given his status as the country's second longest-serving prime minister. The Monash poll was conducted, however, at a time when memories were fresh of his 2007 election defeat, attributed to his overreach on industrial relations and loss of touch on other key areas such as climate change. Another lingering question mark over Howard is whether politics trumped policy achievement: arguably, his government's reform energies flagged by the early 2000s. At the other end of scale, the rankings have also been consistent about who are the prime ministerial failures. Of the also-rans mentioned above, McMahon is rated at the bottom. Others who underwhelm the experts are Harold Holt, who took over from Menzies in 1966, and John Gorton, who inherited the office when Holt drowned in December 1967.

Death in office - or what might be termed the martyr effect - is conventionally regarded as an enhancing agent of leadership standing. Curtin's reputation gains romantic lustre from images of him worrying himself sick during the darkest days of the war, eventually succumbing to heart disease before final victory in the Pacific. On the other hand, the circumstance of Holt's demise - drowning after entering treacherous seas - fails to fulfil the condition of personal sacrifice for the greater good. Kevin Rudd is another who finished well down in the Monash rankings. Not surprisingly, given his precipitous deposition by his Labor colleagues, he was assessed harshly on management of government and party, though fared better on economic stewardship - presumably because of his government's handling of the global financial crisis. One of the most interesting features of the Monash poll is that it was done in collaboration with similar surveys in three comparable Westminster democracies (Britain, Canada and New Zealand). Viewed together, the results hint that opportunities for office holders in the four nations have ebbed and flowed in sync across different eras; in particular, it seems that the timing of a prime ministership in relation to a policy cycle (as it moves through the stages of construction, consolidation and, finally, disintegration) influences the chances of success. Put simply, some leaders are blessed in their timing while others are not, though even the fortunate needs the wherewithal to make good their luck. This brings us back to Julia Gillard. Where will she stand on the ladder of prime ministerial prestige? The short answer is that it's too early to tell since hers is an unfinished story. It is also true that reputations take time to settle after a leader leaves office: passions cool and perspective is gained. Indeed, a prime minister's record undoubtedly comes into sharper relief when compared with that of their successors. If Tony Abbott is elected this September, it will be instructive to see if his performance in office suffers from some of the same factors that have bedevilled the Labor governments since 2007, not least that we seem to be in a void between the exhaustion of the market reform policy cycle and the dawning of a replacement regime.

My hunch is that history will treat Gillard with more sympathy than her legion of contemporary detractors. The rankings indicate that policy footprints matter most to prime ministerial reputation, and on this criterion measures such as the first serious response to climate change, a national disability insurance scheme, national broadband infrastructure and a new education funding system have the makings of a substantial legacy that has been eked in the unfamiliar and inhospitable conditions of minority government. Posterity will better judge this reform program's significance and weight it against her incapacity to parlay the measures into electoral favour. And, of course, there is Gillard's pioneering status as the first woman in the office: a distinction forever hers. How much her gender has coloured the reception of her prime ministership is another thing we will only properly understand with hindsight - perhaps not until the next woman enters The Lodge. Paul Strangio is an associate professor of politics at Monash University and an editor of Understanding Prime Ministerial Performance: Comparative Perspectives (Oxford University Press). Follow the National Times on Twitter