In both Australia and in the British PPP market, much of the research has been framed from either an economic policy perspective, or from a contracting and procurement perspective. Economic policy debates have seen claims and counterclaims emerge between PPP proponents and detractors. In contrast, the procurement-based research has tended to avoid these debates and has focused on understanding PPPs as a new form of procurement.
Much of the previous work evaluating the PPP model in both Australia and internationally is now dated, as the maturity and sophistication of the market has evolved. This is also true of the UK results obtained by Mott MacDonald and the UK National Audit Office. In Australia most research, even some of the most current research, relates to PPP projects that were completed prior to 2004, has concentrated on physical infrastructure such as toll roads, rather than social infrastructure, and were often based on a limited sample of case studies.