The Institute of Public Affairs’ much-criticised intervention in the broadband debate this week, courtesy of a Sydney Morning Herald column by Chris Berg, is a useful contribution to the debate, but not for the reasons you might expect.

Sometimes, you need ideology to explain what’s going on.

Not always. In discussing the financial crisis, ideology inhibits comprehension. It becomes a tit-for-tat left-versus-right obfuscation of a quite simple phenomenon. A handful of key communities - merchant bankers creating mortgage derivatives, ratings agencies endorsing the products - concluded that the barriers to mass fraud no longer existed, and proceeded to perpetrate the fraud. Regulators were hamstrung by complicity (allowing the products be marketed in the first place) and stupidity (being unable to see a problem that was practically dancing naked in the street), and did nothing.

Ideology gets in the way, because it turns something easily comprehended (and therefore punished and guarded against in the future) into an argument about extreme capitalism versus government intervention, and instantly splits along party lines.

In the ongoing — please, when will it end? — broadband debate, however, ideology is more useful, as long as it can be divorced from party allegiance.

Practically the only fact we can regard as proven in global broadband adoption is this: government subsidy drives adoption. This needs no ideology to demonstrate, since all we need is to run down the OECD statistics.

Beyond that, the economist stands on thin ice. Any fool can draw a correlation between rising productivity and rising broadband speeds without proving causation. Does broadband significantly feed productivity, or do they both improve because of factors external to them both?

COSTS LOWER: The same technological developments that probably do drive productivity also contribute to making broadband infrastructure cheaper, more efficient, and faster to deploy. More affordable and more avail- able broadband makes it more attractive to users. For another example, as rising productivity feeds household income, it frees household dollars to spend on broadband.

If economics lets us down, we necessarily fall back to other positions to either support or attack the NBN. The questions become ideological: is equitable access to this communications medium a right? Is broadband a social good or a consumer product? Is the provision of broadband deserving of government subsidy?

In this sense, the IPA’s article is useful, because in delivering a kicking to the NBN, it crystallises the ideological questions. It doesn’t matter that Mr Berg’s descent into abuse starts in the third paragraph and continues throughout. Abusive irrelevancy is where the debate ends up if you press economics to support ideology, because the two don’t inform each other. You can’t attack or defend the NBN on purely economic arguments, because the economics on both sides is irredeemably compromised.

Reflexive opposition to government spending of any kind is just a silly position to take. Countries with no government spending are called “failed states”, and the first world devotes vast resources to try and turn such places into real countries with governments that are able to raise and spend their own taxes.

The IPA’s starting point is ideological, but it’s an indefensible and discredited ideology.

Nor is the price tag on the NBN a useful instrument in the debate. The “$43 billion” is by far the weakest link in the whole plan, a number plucked out of the air which may, depending on the assumptions of the economist or the bias of the speaker, be grossly under- or over-estimated. But that doesn’t mean the ideology of near-universal access to communications infrastructure is discredited.

So if we’re going to have this interminable debate, let’s at least be honest: the broadband debate is, at bottom, a debate over an ideology: whether or not we believe in equity of access to an infrastructure that’s become intertwined with our society.

Richard Chirgwin