"Nowhere does the article say that the investment is solely from the public sector."

Who else should invest in 'infrastructure'? Is it really a good idea for the private sector to own infrastructure?

"I am not sure how they came the figure. One way would be to divide the total value of the assets of the country (public and private) by the number of people who live here. That will give you a rough means of the amount of investment it requires per person to sustain our standard of living. The 12.5% figure means there is an investment of 12.5 man years of investment supporting every man, woman and child."

Wouldn't that give you a really misleading figure. I mean a lot of assets aren't necessary to sustain our standard of living but they exist because they have market value.

"I don't know whether the 12.5% figure is right. But since a house already takes up a fair chunk of that figure, it is in the ball park - definitely within +/- 50%."

Plus or minus fifty percent?!

'Is it really a good idea for the private sector to own infrastructure?' In my opinion no, because we know what happens when they do - we all pay through the nose - on toll roads built and 'owned' for decades by private enterprise in return for the tolls, on exorbitant airport charges when they are sold to Mac Bank, or excessive charges such as on the Cross City Tunnel in Sydney, which could have been built, maintained and paid off in 30 years if it had been constructed for the government on a build-maintain-operate arrangement with private enterprise, for a flat toll of $1.

On the NSW Labor Government, I think they have a close competitor in the race to the bottom of the political barrel just south of the Murray.

I voted for the Party Party Party Party in the first ACT self government election. Under the bizarre modified Hare Clarke system practiced at the time, and owing to the huge number of parties contesting the election, it took eight weeks to find out we hadn't won. Had a good time waiting for the results, though....

David Jennings,

An impressive set of questions. You are obviously putting some thought into this.

I am just taking the most straightforward way I can imagine to measuring to what it costs to add one person.

Take a really simple example. Say an isolated tropical island with 100 people on it. The live in grass huts, wear simple clothes, use simple tools. You want to know how much it would cost to add one person, assuming they live at the same standard at the rest. I would just ask them how long it took them to make all their huts, clothes and tools, and divide it by the number of people there. That would tell you how long it took to build the infrastructure for one person. In this case I expect it would be measured in weeks.

When you look at like this, it is fairly obvious the people in the community have to reduce their leisure time or whatever to build the extra huts, clothes, spears and what. It doesn't matter how it is funded. Maybe they all pitch in, maybe they level a tax and pay tradesman to do it, maybe they insist the new guy take out a loan, pay for new stuff himself, and repay the loan over time, maybe they give a tradesman from some other island pigs to do it. It doesn't matter. It is a closed system. No matter how clever you are with the accounting, the fact remains the community has to sacrifice at least that amount so they can build the new stuff now to accommodate him.

As far as I can tell, Australian is just a bigger version of this island, where everyone has far more stuff.

@David Jennings: Plus or minus fifty percent?!

Valuing stuff involves a lot of hand waving. Fortunately in this case it doesn't matter so much. Whether 2% growth means 12% of GDP, or 30%, the articles point still stands. We would be better off without them.

All this discussion about how much it costs to support the average Australian, but would we be having this discussion if there were no massive government debt, no huge infrastructure shortfall or no housing affordability crisis? Of course not. Instead, we would all be cheering the benefits of high population growth. Clearly, there are very substantial problems coping with the current rate of population growth, so why continue such a strategy when the problems are so apparent and the benefits so nebulous? How much more damage must occur before this failed population growth experiment is curtailed?

Some useful comments above from VK3AUU,:

"You need to include everything imaginable, suburban streets, street lighting, sewers, water and gas supply, freeways, rail networks and rolling stock, airports, power stations and distribution systems......."

and rstuart:

"I am not sure how they came the figure. One way would be to divide the total value of the assets of the country (public and private) by the number of people who live here. That will give you a rough means of the amount of investment it requires per person to sustain our standard of living. ......"

Also the valuable comments from Rhian:

"At issue is the article’s inference that we need to increase infrastructure spending by 12.5% of GDP to raise output growth by 1%.

Since 1959 Australia’s annual public investment as a percentage of GDP has averaged 6.6% a year, while real output growth has averaged 3.6% a year. So the claim is clearly wrong."

I thank VK and rs for putting the infrastructure cost concept so clearly.

All of this points to the need to get actual real data on infrastructure costs; only then can we get to what is needed initially ie the total value of currently existing infrastructure, to get a per capta value.

Infrastructure must first be defined, and terminology established; no easy task. This must include all conventionnal infrastructure (narrow), as well as human infrastructure (broad).

I would include in this broad definition, human infrastucture component eg cost of the skills base, training Doctors, Nurses, Engineers etc

I believe Governments have much of the data already; but are loathe to disclose it, because to do so destroys the economics of their high population policies, leaving the Emperor with no clothes.

My own view is that infrastructure costs, even on a narrow basis, are of the order of $300,000 to $500,000, per extra person; this is expenditure needed to avoid dilution of the base. ( I can provide some substantiation)

Thanks to Jane for the serious work and for getting the issue up for discusssion. Can you do more or persuade another academic to take the research further?

No Fester, I would not be cheering the benefits of high population growth under any circumstances, although I agree the current situation does give the debate more traction.

In the eighties when housing was affordable immigration was much lower, and no-one mentioned it or demanded a higher intake. In fact, if anyone had said we should bring in hundreds of thousands of immigrants and by the way, did anyone object if that meant housing would double in price, you can guess what the answer would have been.

What is so wrong about our current high immigration level is that it was done by stealth and with no mandate, and outside big business there seems very little support for it.