Ascribing hero status to a bank these days is a bit like being nice to Ronnie Biggs. But there is little doubt that ACC's pursuit of developer Liam Carroll through the courts has been of enormous benefit to the Irish taxpayer. For the moment that service can be explained only in terms of how the bank's legal action has clarified what a danger Nama could be to the restoration of Ireland's fortunes – indeed, how utterly destructive it could be. However, if that welcome transparency encourages enough people – opposition politicians or ordinary members of the Green Party – to better articulate their reservations about Nama, and perhaps change it or stop it altogether, ACC really will have done the state some service.

Last month, when the Nama legislation was published after months of speculation about what it might contain, the fashionable response was that as the agency was now the only game in town, it behoved us all to accept the reality of it, throw away our attachments to alternatives like temporary nationalisation and move on. I must confess that I fell for this line myself.

Then ACC went after Liam Carroll and was backed successively by the High and Supreme Courts. Suddenly, we had before us specific details of how badly Irish developers were doing, how hopelessly indebted they were and how little their developments were actually worth. The ACC action filled in much of the information deficit that had existed about how Nama would interact with and manage the estimated €90bn in toxic loans that are due to Irish banks. It is a terrifying prospect.

What has come into sharpest relief is that Nama is not built on hard evidence, on facts and figures, on well-supported projections, or on reliable pricing models. It is based on hope and optimism and on a belief that everything will be alright on the night. Nama will pay more for loans than those loans are worth (thereby recapitalising the banks) in the hope that they will, suddenly, majestically, rise in value over the years, leaving the taxpayer in clover. The whole process is a mirror image of the kind of blind optimism which got us into the mess in the first place – throwing money at undeserving candidates on the basis that things will get better and better.

There is not a shred of evidence for such optimism or for the belief that at some mystical point in the not too distant future, the taxpayer will be quids in. In the late 1980s and early 1990s, Japanese property prices were subject to the same boom and bust as we have seen here recently. Apartments that had jumped in price from the equivalent of €181,000 to more than €500,000 collapsed in value before settling at about €290,000 for well over a decade. Even now, almost 20 years after the collapse, property prices in Japan are about 40% off their peak. The details in the ACC case suggest even worse collapses in property values have occurred here, and that there is not the remotest chance of them climbing in any significant way over the next decade. There is no realistic prospect that taxpayers can expect to break even, let alone emerge from the whole process in actual profit for a long time to come. When critics of Nama suggest that children born today will be paying off the agency's profligacy in their first wage packets, they are closer to the truth than such hyperbole might initially suggest.

So what is to be done? The Liam Carroll case has emboldened some of the opposition spokespeople to revive criticisms of Nama which had been muted since the legislation was announced. But it is to the ordinary members of the Green party we must turn for any hope that the agency might be stillborn.

Last week's reports that party members all over the country (although not in Leinster House) were increasingly concerned about Nama were a welcome sign that a lively heart still beats in the damaged old Green body. Several sections of the party have demanded a special conference to decide Green policy on Nama, and were one to be held, and two-thirds of delegates were to vote against Nama, the party's TDs could not vote for it in the Dáil. Assuming all the opposition TDs voted against it, that would be the end of Nama, and of the government. As this would be one of the best day's business in the country's history, we can only hope that the grassroot Greens get their way.

Emily says It's a load of Áras: But is it?

Recent speculation about the possible identities of the candidates for the next presidential election took an interesting turn last week when Ombudsman Emily O'Reilly wrote to Phoenix magazine to deny that she had ever intimated to anyone that she had any interest in running for the Áras. "Such actions," she wrote, "would be entirely inappropriate in my role as Ombudsman and Information Commisioner".

This letter was subsequently reported as being a categorical denial by O'Reilly that she wanted to replace Mary McAleese. It was no such thing. Nowhere in the letter did O'Reilly say she didn't want to be president. In fact, her missive left wide open the possibility that she would do her patriotic duty should any party wish her to represent them. This one could run for a bit.

ddoyle@tribune.ie