The Productivity Commission has criticised the process of moving to a go-ahead for Capital Metro from the point reached in a submission to Infrastructure Australia in 2012.

That does not necessarily imply they conclude the project is of doubtful validity. I sense they are instead criticising a gap in the decision-making logic without actually having the data to finally judge the project options. The submission in 2012 for preliminary funding showed better benefit-cost ratios for Bus Rapid Transit options than Light Rail Transit Options because of the lower capital cost of the former.

However, the two types of projects would not be equal on other grounds, and I think this is where the gap in economic and business cases has not been filled (at least in terms of public disclosure). Light rail will be better for value capture in relation to property development, based on overseas experience. The economic benefits of densification along transport corridors, and so-called agglomeration productivity benefits, are areas where our local experience in cost-benefit analysis is perhaps at the learning stage, but that is not to say that one cannot judge that they will be valuable.

In addition to the projected fare revenue and the lower operating costs of trams versus buses, I understand the ACT government had previously pointed to car parking revenues and this relatively new area of ''value capture'' as two key prospective financial benefits.

No one has yet done justice to analysing these factors in a publicly available study. The Nairn report for the ACT Liberals, which claimed the Capital Metro project would be unviable, seems to me to have a few major holes in terms of financial analysis. A long-term project was evaluated over less than its effective economic life, using 100 per cent debt funding paid off over 15 years, but assuming that the project was worthless after repaying the debt.

To assume a project is worthless in 15 years' (or even 30 years') time would necessarily pre-condition the result of such an analysis and make it a misleading exercise. And that is not to criticise Bob Nairn's transportation knowledge - it just says that the financial analysis (as distinct from his analysis of the transport issues) could not have been complete and must, to that extent, be unsound. I can't tell how this might have affected the end result, as I don't have all the data.

However, Mr Nairn's table of figures seems to project a stabilised fare revenue of only $2.2 million per annum. Simple arithmetic says that at an average light-rail trip fare of circa $4.50, this revenue estimate implies only about 1300 paying passengers per day, or six to seven full vehicles. Unless I am misinterpreting his analysis, that seems ridiculously low and would be a second doubtful element in terms of reaching a sound conclusion as to project viability.

I hope I am not being too unfair to Mr Nairn, but what I read didn't convince me that we have the full picture as yet. And, as a visitor, I cannot understand why the parliamentary and government offices area south of the bridge would not be a viable future route.

It is not just locals one should provide for, because if Canberra Airport goes international, future tourism potential is another major beneficial factor.

Ian F. Bell, Sydney, NSW

One fact overlooked in the debate over light rail is the extent to which the scheme will lock the ACT into inflexible, expensive technology likely to be rapidly superseded. Propulsion systems for both buses and trams are changing rapidly. Emerging electric and hybrid systems can recharge in 30 seconds, doing away with overhead wires, and, in the case of non-rail systems, providing route flexibility.

In an era of rapid technological change and constrained energy supplies, it cannot be logical to lock into yesterday's technology with a single massive bet on light rail, when incremental investments in progressively more capable buses are possible. It is surprising that neither the Greens nor the Productivity Commission seem to have considered this.

Jim Lumbers, Red Hill

It is all very well for David Dawes (Letters, July 14), CEO of the Land Development Agency to say that there has been extensive consultation on the Yarralumla Brickworks Planning and Development Strategy, but his agency has not listened to or acted on the feedback from residents.

The latest strategy is at odds with the key outcomes of the consultation process, as identified in the LDA's own Consultation Summary Report May 2011: maximum building height has gone from four to eight storeys; the essential Cotter Road and Adelaide Avenue interchange has been omitted; the Brickworks itself will not be developed; and there is an absence of the shops and amenities needed to create a vibrant community. Engaging without listening is not consultation.

Peter Hatcher, Yarralumla

I recently visited the arboretum. On the day I went it was well patronised, mainly by families enjoying themselves. As it develops it will certainly become an attractive asset.

I understand the land was previously a pine forest destroyed by fires in 2003. Around the same time in Maleny (Queensland) the council was able to purchase a large tract of land (formerly dairy farms) adjacent to the town. However the Maleny citizens with their foresight and inspired planning opted to go one better than Canberra planners: they decided they wanted a golf course!

Ian Pollock, Maleny, Qld

The article ''Dancing, tears over women bishops vote'' (July 16, p9) includes the sentence: ''For the first time since Christianity arrived on [sic], the church in England can be led by a woman.''

According to Canon A 7, Of the Royal Supremacy: ''The Church of England acknowledges 'that the Queen's most excellent Majesty, acting according to the laws of the realm, is the highest power under God in this kingdom, and has supreme authority over all persons in all causes, as well ecclesiastical as civil'.''

The Church of England, therefore, has been led by a woman since 1952, and previously by other women.

Her Majesty has to give her royal assent to allow women to be bishops, and presumably herself to be the ruler of the Church of England, which she has already been for the past 62 years.

J. Evans, Deakin

So Australian National University vice-chancellor Ian Young is concerned about university funding if deregulated fees are not brought in (''Survival of the deregulated'', Times2, July 15, p1)? Maybe he could consider reducing his million-dollar salary package or the huge number of highly paid executives at ANU (multiplying rapidly in recent years) or their highly paid ''sales trips'' around the world. Or perhaps he could act to stop the bullying of staff that is rife at ANU, which costs the university so much money.

But no, he would rather try to get students to pay $100,000 to $200,000 a year in fees so he can sustain these wasteful practices. It's time he stopped crying poor and putting the cost of his extravagance and his incompetence onto students. Imagine how many world trips he will get and the pay rise he can seek if fees are deregulated. University chiefs have dollar signs in their eyes when they talk about the deregulation of fees. But it is our young people who will suffer the crippling costs.

F. Landau, Dickson

Ian Young first championed student fee deregulation as the only way to turn the ANU into Australia's Harvard. Now, in his article, he takes another tack. Decades of voter neglect have led governments to squeeze universities: ''Universities are expanding rapidly with fewer dollars per student.'' Costs to government have soared, leaving no one happy - deregulation is the ''lifeline'' and he is the hard-headed pragmatist.

Except the argument is full of holes. It's true, as he says, that government funding per student fell between 1997 and 2012. But much of this was cost-shifting from governments to student fees, leaving universities no worse off. Some was due to indexing of government grants below inflation, leading to erosion of government funding. But in 2012 government funding was indexed to relevant wage inflation. So funding per student is stable under the current system. Is that ''unsustainable''?

Perhaps Professor Young meant the rising costs to government are unsustainable politically? But that concedes too much even on his own terms. If rising HELP debt is unsustainable, what does he think will happen if university fees are uncapped?

It's just not true that deregulation is the only response to government plans to slash funding for higher education. Fees could remain regulated but take up the reduction in subsidy - not ideal if you think education is a public good but far from a dangerous aspiration for the ''US model''.

Or better, fees could be regulated at the cost of providing the student's education, after subsidy. As Professor Young has said, universities already overcharge their students to plump up their research funds. Surely that's not why the elite research universities now want to be able to charge whatever they want.

Tom Swann, Campbell

Overheard in Parliament House this week: ''Listen, sweetie, I say what goes here. You're a mere bureaucrat and you do what you're told. Understand? Clerk of the Senate, experienced constitutional lawyer, statutory officer. Don't mean a thing to me. In the private sector, we just get things done, and we know who's boss. No arguments! So get those bloody provisions drafted, or get out of the road. And by the way, out in the real world nobody gives a fig for Canberra fat cats like you.''

D.A. Nolan, Nicholls

I did not have children by choice but I have dedicated most of my life to make this planet a better place for future generations. If the predictions are right, Australians and our politicians, through the repeal of the carbon tax, are willing to sell off their children's, grandchildren's and great-grandchildren's future for about $5 a week - an amount that would have reduced substantially over time. I believed our future was worth $5 a week.

Those who supported the repeal of the carbon tax have taken a step backwards in protecting future generations from the consequences of climate change, which we know will be significant.

Be it on your heads. I and those who care about the planet and preserving it as a liveable place for future generations will persevere. But I admit, with no children, I do have ''bugger the lot of you'' moments.

J. Nesbitt, Page

So former Commonwealth Bank chief Ralph Norris wants to know what can be done to prevent corruption and fraud in large organisations such as the CBA (''Former CBA boss Norris blames scandal on 'rogues''', canberratimes.com.au, July 14).

Gee, Ralph, I know it might seem a bit radical but I reckon if an occasional high-profile chief executive or board member spent some time at her majesty's pleasure, or if just one was sacked for failing to do the job they are paid millions to do, things would change pretty quickly.

In the meantime, engaging in hand-wringing and mumbling self-serving platitudes is not only offensive, it seeks to excuse while compounding the crimes committed.

John Richardson, Wallagoot, NSW

My letter of July 7 asked a question: How are the recent interceptions different from hijackings?

I wrote in the hope people better informed would clarify the matter. A fair-minded reader would understand that. The intention was simply to raise the question, not - as is mistakenly supposed in T.J. Farquahar's sarcastic response (Letters, July 9) - to make assertions with an implied claim to expertise.

Mr Farquahar notes that the formulation used by the UN High Commissioner for Refugees is less than categorical - ''may breach obligations'' rather than ''is in breach of obligations''. But that comment (formulated with diplomatic caution) does not relate to the interception (alias hijacking?). It is about returning people to a country that will jail them or worse for having left without an exit visa.

Thomas Mautner, Griffith

A new survey about a proposed "scores on the doors" scheme in the ACT is hard to swallow (''Hygiene fears at foodies' hearts'', July 14, p1).

Firstly, there is no evidence to show that food hygiene standards have slipped in the ACT. Indeed, the ACT government's health agency recently told industry leaders notices issued to food businesses are "static" in Canberra and the number of prohibition orders has fallen.

Every hospitality business must now have a food safety supervisor on staff to uphold food safety standards, following a new ACT government regulation.

The current recipe for food safety standards is working and there's no need for further regulation.

Customers should feel confident about dining out in Canberra and proudly enjoy the city's wide-ranging, innovative and award-winning hospitality venues.

Brad Watts, general manager, Australian Hotels Association (ACT)

Recent articles in The Canberra Times have canvassed concerns about hygiene in food preparation. Outbreaks are rare but need not occur at all.

Most cooked food is sterilised by heating and served hot, but some foods like preserved meats are served cold.

Takeaways and home deliveries are only warm when served. Perhaps they should carry a heat-sensing patch on their containers confirming they have been heat-sterilised.

However, many foods are eaten cold and would be spoiled by heating.

Just as we use high-powered radio from a magnetron in our microwave ovens, there may be a need for a source of ionising radiation to kill pathogens in cold food. Radioactive cobalt-60 could do the job but how to tame it would be a real problem, one for CSIRO perhaps.

Colin Glover, Canberra City

AMERICAN SHAME

Having watched Foreign Correspondent on the ABC on July 15, I am totally disgusted with the reported assistance of $US12 million annually by the United States towards the clearing of cluster bombs from Laos. For a country, reputedly the richest in the world, to pay such an abysmal amount to a country which was, in effect, neutral and so poor, should be an ongoing shame for Americans.

Bernie Walsh, Kambah

BEWARE THE MAGPIES

I can do one better than Colin Parks (Letters, July 15) with an early magpie attack; I was swooped on July 9, in the early afternoon, while riding my bicycle along Phillip Avenue, Hackett. It seems time again to don my helmet with cable ties on!

Sep Westerhuis, Harrison

MOW DOWN GENDER GAP

No anecdotes, Jenna Price (''Bridging the gender pay gap begins at home'', Times2, July 15, p5) but I assume that your female unpaid percentage of the household work takes account of mowing the lawn, putting the garbage out, installing irrigation systems, garden maintenance, replacing roof tiles, etc.

Steven Hurren, Macquarie

NONE OF OUR BUSINESS

Why is Ian Thorpe's sexuality noteworthy? Surely it is for him to know and none of our business. The one thing to be admired and celebrated whenever we speak of those in sport who touched the stars, is the phenomenal performance of Thorpe the swimmer. Let's settle for that and let him get on with life.

Peter Funnell, Farrer

In the circumstances, I understand Ian Thorpe admitting to being a homosexual, but in general do we, the public, really need to know about the sexual preferences of others? That's their business.

Evelyn Bean, Ainslie

WAR NOT OVER, BOLT

Speaking of Andrew Bolt, this is the man who not long ago, dressed in his flak-jacket in the safety of the ''Green Zone'' in Iraq, informed Australia and his beloved bloggers that the war was won and over in Iraq. What next? Bolt tours of downtown Baghdad.

Richard Ryan, Summerland Point, NSW

McGRATH DEFIES BELIEF

Incoming Liberal senator James McGrath wants the GST to rise, the health and education departments abolished, says it's OK to make homophobic remarks and, of course, wants to sell off the ultra-left-wing ABC. The man has done what I hitherto thought impossible: make Cory Bernardi look like a moderate.

Thos Puckett, Ashgrove, Qld

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