The closest thing to a quantification comes in the Grattan Institute's submission to a Senate inquiry on tax deductions, which finds that limiting negative gearing could have a one-off impact on house prices of between 1% and 2%.
"It's a one-off impact based on returns to investors being lower," he said.
Let me explain: Currently the Government assesses how a policy change affects people by carrying out a one-off impact assessment.
That means the one-off impact of that El Nino event was equivalent to about 20 years of the expected background warming trend So, unsurprisingly, 20 years later, expected temperatures have risen so that an average year is now as warm as that exceptionally hot year.
While any given technological breakthrough may seem to be random, Romer considers that new technological developments, rather than having one-off impact, can create technical platforms for further innovations, and that this technical platform effect is a key driver of economic growth.
Since it is a one-off offer with no impact on reputation, the "rational" responder behavior is to accept all offers, no matter how unfair.
The beat was driven largely by a £22m one off impact linked to the introduction of Solvency II and the Scheme of Demutualisation.
Ms. Glassman said she believed that a run of exhibitions, even if small, would have a greater impact on audiences than a one-off.
Jarvis said any sums raised by a one-off levy would make a significant impact on the government's finances.
So that impact is a one-off.
First, that last week's horror will remain a one-off, and that its confidence-shattering impact will gradually diminish.
