A city's health is dependent upon that of the public realm

Brisbane Lord Mayor Campbell Newman's proposal to use the private sector to build and operate new council facilities, such as libraries and pools, deserves serious debate.

This means taking the discussion beyond the confines of financial analysis to consider the social implications of the proposal.

Presumably the idea is not driven by the need to plug any gap in council finances that the tunnel plans may create. This would represent a reactive, and ultimately ineffective, way of planning for municipal social and physical infrastructure.

Australian metropolitan management has been plagued by decades of ad hoc and reactive infrastructure planning and delivery. The consequences of this are especially evident in our urban transport "systems", which are poorly integrated and whose planning and operation are dictated by an increasingly complex array of competing interests.

In Melbourne, the privatisation of public transport has added to system complexity and dysfunctionality - a process that some scholars call "splintering urbanism". It has blurred the focus on what must be the overriding goals of an urban transport system: sustainability, accessibility and equity.

Thankfully, in southeast Queensland things have recently gone the other way. The state's new Translink system, which was strongly supported by the Lord Mayor and Brisbane City Council, represents a major re-integration of public transport services, which has already produced service improvements and higher patronage levels.

Would the entry of the private sector into social infrastructure provision also contribute to splintering urbanism? Very possibly, because the logic of the market is ultimately irreconcilable with many of the broad community interests served by public facilities.

Public infrastructure, and the public domain generally, exists to address important areas of market failure or under-provision, not all of which relate to financial imperatives, such as the pricing and funding of public goods.

Like public transport, our system of municipal social infrastructure - community facilities and spaces - serves a set of overriding public interests. For social infrastructure, these are: service access, social equity, and community solidarity.

The first goal is straightforward. There are many vital social services that the private sector will never want to supply because they are not inherently profitable.

Libraries are a case in point. Traditionally, governments have provided such facilities, though in recent years some have used private operators propped up by public subsidy. The argument that publicly subsidised private provision is more efficient tends to fail when one takes into account the broader effects of service splintering (contract administration, planning fragmentation, and so on).

The second rationale for social infrastructure - equity - is equally straightforward, even if it tends to get lost in technical debates about service reform. The public domain exists partly to ensure that everyone has the opportunity to use the services and facilities that are fundamental to human wellbeing.

The third rationale for publicly provided social infrastructure - community solidarity - is grounded in one of the fundamental tenets of liberal democracy: the need for a public realm that supports and nourishes civic values and obligations.

Indeed, this may be the most important reason for a public realm. Liberal democracy is deeply premised on the need for a civic sphere outside the immediate reach of private interests (markets, families, and so on) where the basic values and obligations of citizenship are learnt and upheld.

Public spheres are where all citizens - irrespective of socioeconomic or cultural background - are welcome and where the rules and norms that are fundamental to democracy are cherished. Importantly, the public realm is a sort of "civic school" which newcomers (the young, migrants) and outsiders (such as gated communities) can experience and learn key democratic values, such as tolerance, equality of treatment and mutual obligation.

The great project of building Canberra - supported by all sides of politics, especially the Menzies Government - was a specific instance of how a growing and flourishing public domain assists the broader development and strengthening of liberal democracy.

It is no exaggeration to say that the health of a democratic body - a city, a nation - is reflected in, and dependent upon, the health of the public realm.

And so, will the proposal to allow the private sector to provide municipal social infrastructure harm Brisbane's public realm? The answer is surely yes, because the mixing of market and civic functions will blur the purpose of the public realm and send confusing signals to the citizenry about the fundamental democratic rules and values.

The market already has plenty of space - indeed, it now occupies more of our "lifeworlds" than ever before. A splintered public realm might well shatter the broader bases for our democracy.