Conclusion
The conclusion first assesses the prime ministers against the criteria set out in the introduction: their longevity, their control over their parties, and their ability to shape the agenda. The first two can provide evidence of those who were successful. Noticeably those who brought their party from opposition to government were those who were likely to flourish. Second, the conclusion explores the difference between the four political systems and the impact they have on the working of the prime ministers. It identifies the variations in cabinet practices and the degree to which cabinet remains a consistent decision-making forum in Australia and New Zealand but less so in Britain and Canada. It concludes by stressing that much of the difference can be explained by the levels of accountability prime ministers have to their parliamentary colleagues, rather than a broader party electorate: a choice between competing principles of party democracy and accountability.