Economists like to think that there are two essential things that we need to live: food and shelter. Today I am going to argue that there is a third, often overlooked, sine qua non for life: reliable information.

Without information on what flora and fauna was edible, where it could be found, and how to collect and prepare it, our forebears would not have been able to eat. Without knowledge, which is just stored information, on how to build safe and habitable shelter, our ancestors would not have survived outside. Information is so intrinsic and obvious that we tend to take its supply for granted. But this then begs the question: where do we get our information from?

In thinking about this question, I want to start from first principles. Imagine that I asked you to construct a new society from scratch. Think about the 'services' your community might demand from its government in return for citizens paying away a big chunk of their labour income in the form of tax.

There are the immediate candidates: a legal system; property rights; enforcement of the rule of law; basic utilities; public transport arteries linking suburbs and cities; health and education; a defence force, and so on.

Yet there is another, undepreciated, public service that we know modern societies have determined they need in order to connect their citizens together on a daily basis, to empower them to make the best possible decisions, to enable an objective appraisal of the performance of government, and to more generally foster democracy. I am talking about free, readily accessible and credible information.

Consider the role of the Australian Bureau of Statistics (ABS) and its equivalents around the world, such as FedStats in the US or the National Bureau of Statistics in China. Taxpayers pay these agencies to collect and disseminate vital socio-economic statistics on almost all measurable things, including life expectancies, fertility, population change, unemployment, incomes, inflation and economic growth.

Ordinarily, this information is available to everyone for free and, one way or another, forms the basis of all our decision-making. For example, we analyse ABS data to understand how rapidly the economy is growing, how quickly the cost of living is changing, the extent of poverty and income inequality, whether interest rates should rise or fall, how much money the government needs to spend to modulate extremes in the business cycle, how rapidly the population has expanded, and the ensuing urban planning and infrastructure needs.

And directly or indirectly, we also use these data to audit the performance of democratically-elected governments.

Because this information is such a fundamental part of the fabric of a healthy society, and because it needs to be made costlessly available to everyone, it is hard for the private sector to provide all of it. This is, therefore, a good example of what economists like to call a 'public good'. Other examples include the air we breathe, the military, or our legal system.

A public good is something that when consumed by one person does not reduce its availability to another (we can all study as much ABS data as we like, but food is a finite resource), and once it is made available it is hard to restrict others from accessing it (the only way to stop you from benefiting from the defence force is by kicking you out of the country).

In economics, the 'public good problem' arises when we cannot be certain that private markets will produce the quantities of these services desired by the community. And so we pay taxes and elect politicians to ensure that government gives us the hospitals, roads, rail, water, sewerage, electricity, and emergency services that the country requires to function in the manner we expect.

There are, of course, grey areas where the private sector chooses to offer us additional services for a higher price. Thus we have private schools, hospitals, toll-roads, and data providers, amongst others.

One service that western democracies have decided must be freely available is regularly transmitted and (notionally) unbiased news and current affairs. With this objective in mind, almost all countries have established a 'public broadcasting service' (PBS). In the UK they have the BBC, Canada has the CBC, New Zealand TVNZ and Radio New Zealand, and the US a decentralised network of stations called the PBS.

In each nation the PBS is freely accessible to members of society via the main mediums: originally it was radio, then TV and now the internet. While private markets have always supplemented this core news with a great deal of other, more monetisable 'content', policymakers have universally concluded that the state must produce, and protect the integrity of, a minimum level of objective information. In Australia, this manifests most strikingly in the form of the ABS and the ABC.

No matter what technologies come and go, which businesses rise and fall, what agendas private proprietors push, which natural or man-made catastrophes threaten civil society, all Australians know that, irrespective of their income or station, government will offer them access to dependable current affairs information via the ABC. Indeed, the ABC's remit extends beyond just news to regional and early childhood programming.

The value and viability of the ABC in turn hinges on its ability to rapidly propagate bias-free information throughout the community. Private content providers, such as The Australian, AFR, Wall Street Journal, and The Economist tend to have quite explicit economic, political and policy agendas that advance the interests of their readers and/or proprietors. That is their prerogative.

The private media manufacture content that they either make available through (relatively) free-to-air channels like TV, radio or the internet, and which is funded by advertising revenues, or which they restrict access to using 'paywalls', such as cable in the case of FOXTEL, or newspapers that one must pay for.

There are sound reasons why no mainstream private media organisation in Australia produces free daily content that remotely resembles the ABC's 7.30 Report and Lateline (or, for that matter, the weeklies, Four Corners, Q&A, and Media Watch). In short, these shows do not offer adequate commercial returns. The best we have is Channel 10's Meet the Press early on a Sunday morning.

Instead Channel 7 and Channel 9 enthral millions of viewers with Today Tonight and A Current Affair, which are readily monetisable, mass-market programs. After years of indulgence, Channel 9's 60 Minutes was dumbed-down because its more serious fare was not commercially tractable. For similar reasons, The Bulletin magazine was shut down. And it is a very awkward truth that our only truly 'national' newspaper, The Australian, has been irregularly profitable, and in different hands would not exist today.

Here it is also useful to remember that Sky News, which is a late addition to the current affairs game, is a closed, subscriber-only network that is forcibly bundled together with other costly services. Despite claims to the contrary, Sky News could never substitute for a PBS.

Whatever news and analysis is yielded by the private media is always subject to the editorial and commercial influence of their owners. As is his right, Alan Jones at 2GB projects a forcefully conservative line, as does the Editor-in-Chief of The Australian. And these prejudices will vary as the management and business owners change over time.

But the mere fact that The Australian has long waged a campaign to promote conservative economic and political interests demonstrates that, by its very construction, it is incapable of fulfilling the functions of the ABC.

The most successful private media content is normally found not in news or current affairs, but in areas where consumers are willing to part with hard cash: entertainment. Think movies, mini-series, sports, and hobby shows. With the exception of, say, bowls and suburban rugby, this is not the domain of the ABC, but the purview of private companies. Indeed, it sheds light on where the ABC should not stray.

It is probably now clear that these thoughts are motivated as a response to criticisms from industry and academics that the ABC is 'crowding out' private activity and, at the limit, should be abolished altogether.

As one example, the highly regarded bipartisan academic, Professor Stephen King of Monash University, recently took his fight to the ABC via an op-ed published in the AFR. Professor King claimed that "traditional newspaper owners have a legitimate gripe" with the ABC and BBC vigorously cross-promoting their internet, audio and video news, and maintained that "this competition is clearly unfair".

He also made the case that taxpayer funding of the ABC and BBC gives them an unreasonable advantage in experimenting with technology platforms that in turn make it "difficult for the private news providers to compete".

The crux of Professor King's argument is that the internet, which is currently awash with freely available news (at least until it is placed behind paywalls), has eviscerated the need for a national PBS. He has called on the Government to revisit the role of the ABC, and suggested that it might be time to "pull the plug". Professor King best encapsulates his position with the rhetorical question, "Should taxpayers be funding the ABC to compete against private providers who both want to and can do everything that the ABC can do?"

While I consider Professor King a friend, I would submit that his analysis is flawed.

First, the ABC has been in the news and current affairs business, which is its public mandate, for nearly 80 years. The real question is whether traditional media can make money by supplying the same thing. It is little different to the difficulties experienced when private companies try to compete in the provision of core health, education or transport services.

The empirical evidence locally and overseas indicates that media companies have a higher probability of generating profits by concentrating on non-commodity areas, such as entertainment, or by specialising in highly 'value-added' content that consumers and/or advertisers are willing to pay for. The Economist, AFR, WSJ, Financial Times, Business Spectator and Crikey are all good examples of the latter.

Second, it is wrong to allege that "private providers ... want to and can do everything that the ABC can do". Most private media charge for their content, have explicit commercial and/or political biases, and cannot guarantee what information they will supply or its frequency. If it is not economic to produce, say, The Bulletin or Four Corners, they will not do so.

Third, the national PBS has a responsibility to the community to make its news and analysis available to them via every conventional medium, including radio, TV and the internet. The ABC already offers a 24-hour textual internet news service. Its extension of this to 24-hour free-to-air digital TV at no incremental cost to taxpayers is just smart management.

Fourth, it seems odd to argue that a PBS has a comparative advantage in technology innovation over private companies. To the best of my knowledge, most media technology these days is developed by third-parties, not content providers. And the ABC's prone-to-fail technology could hardly be described as cutting-edge.

Fifth, and arguably most significantly, the real threat faced by traditional media companies has nothing to do with the PBS, which has always been a part of our informational landscape. The redundancy in their business models has been crystallised by the transformative influence of the internet, and its destruction of historical barriers to entry.

In this respect, the sector most adversely affected has been newspapers, and for obvious reasons. Cable, TV and radio companies continue to thrive. Newspapers, on the other hand, have, in effect, lost their grip on two oligopolies.

The first was the highly lucrative employment, real estate and auto classifieds. As these crucial revenue streams migrated to new online competitors, such as realestate.com.au, seek.com.au and carsales.com.au, traditional newspapers have been devastated.

The second oligopoly was conveniently-accessed (and mobile) morning news. Yet now most of us get the same information for free as soon as we switch on our ubiquitous computing devices.

The 'old news' being produced by the print media's teams of journalists was not being funded by the price consumers were willing to pay for that service - the buck or two cover charge for the paper - but by the classified revenues.

Once the classified returns evaporated, the news business it was cross-subsidising became non-viable. It has just taken a while for the grey-heads to realise it.

If these business models are to endure, they must adapt. Consumers don't value news sufficiently to cover the costs of the existing infrastructure. This means that these expenses will have to be cut or removed altogether. And traditional media will have to shift away from commodity news and manufacture deeper and more differentiated content that people will pay for.

Most of the missiles directed at the ABC amount to little more than the straw-men erected by incumbents that have witnessed their once highly profitable industry structures irreversibly change for the worse. My advice is to make like the apes or accept extinction.

The ABC's challenge is to maniacally commit to never contaminating its primary product - credible and reliable information about the society in which we live - with any form of bias, or the perception of such.

These are Christopher Joye's private views and do not represent the opinions of any organisation with which he is associated.