The inference to be drawn from that statement was, the Defendant suggested, that her Honour intended to adopt a figure for average weekly earnings, but incorrectly identified it as the figure applicable in eight years time. It was conceded that her Honour might have adopted a figure other than average weekly earnings if of the view that Tamara had demonstrated above average abilities, but the judgment does not suggest such a conclusion. Accordingly, her Honour erred in principle in taking a figure at a future date.
22 This exercise, it was submitted, also demonstrated the third error in approach, namely a failure to calculate a lump sum based on deferred enjoyment, as earnings would not commence for some eight years (or possibly 10 years if tertiary education were taken into account). The Plaintiff did not challenge the principle that deferred commencement should be reflected in the outcome, but argued that the kind of mathematical precision proposed by the Defendant was not appropriate.
23 Each of the second and third complaints made by the Defendant have substance, as a matter of principle, but the first, as already noted, does not. If there had been no appeal in relation to liability, questions of assessment would only have come before this Court on an application for leave to appeal. Given the manner in which the case was conducted below, leave might not readily have been forthcoming to agitate these matters.
24 Nevertheless, if the points of principle have merit, this Court may be required to reassess future economic loss on the basis adopted by her Honour, but making appropriate corrections to the calculations. Given that the matter is dealt with by way of rehearing, the relevant calculations should be undertaken as at the date of judgment in this Court, but no current figures were provided by the parties. Accepting her Honour's assumptions that the Plaintiff would commence work at 18 and enjoy an ordinary working life of 47 years, a 3% multiplier should be applied for that period. The amount so calculated should be further reduced according to the 3% deferred multiplier for a period of eight years, the plaintiff being ten years of age at the date of judgment.
25 The calculation proposed by the Defendant on appeal adopted a figure of $807.70 for average weekly earnings of all persons, at the date of trial. Use of this figure was sought to be justified by reference to the judgment of Mason P in Rosniak v Government Insurance Office (1997) 41 NSWLR 608 at 621F-622C. However, I do not read that passage in his Honour's judgment as supporting the approach suggested. It is devoted to rejecting the argument that median wages, rather than average wages, should be the relevant yardstick. In State of New South Wales v Moss (2000) 54 NSWLR 536, calculation of future loss for a female student was undertaken by reference to the average net wage for full-time adult female workers in New South Wales: no issue was taken with that calculation in that case, and no reason was presented to this Court to support the conclusion that the adoption of that yardstick by the trial judge involved error. In my view it did not. However, the tables relied upon by the Defendant in her submissions show that the average full-time weekly total earnings of adult females in New South Wales, as at 21 May 2004, were $913. The same tables indicate that, in round terms, the net wage after income tax, on that figure, would be approximately $700.
26 Multiplying that figure by the relevant 3% table for 47 years (1,325.3), reducing the result by 15% for vicissitudes, and taking 10% of the result, being the plaintiff's diminution of earning capacity, produces a figure of $78,855. Applying to that figure the 3% deferred table for eight years (.789) results in a sum of $62,216. As was noted in the course of the hearing, no allowance was made by her Honour for the six months during which the Plaintiff would be unable to work following anticipated surgery, nor for the usual 9% on account of lost superannuation, nor interest. If these factors are taken into account, as it would seem they should be, the ultimate result is in the order of $80,000, a reduction of $20,000 on the figure allowed by her Honour.
27 The principle that the Court should not order a retrial, even where error has been demonstrated in the proceedings below, unless "some substantial wrong or miscarriage has been thereby occasioned" is now to be found in Part 51, r 23 of the Supreme Court Rules. As noted in Conway v The Queen (2002) 209 CLR 203 at [27] and [28] the principle derives from the general law and is consistent with long-standing practice in civil cases at common law in New South Wales. That practice derived from appeals with respect to jury trials. In relation to other appeals, the powers of this Court are identified in s 75A(6) and (10) of the Supreme Court Act 1970 (NSW). The power to give a judgment which "ought to have been given" in the Court below permits the dismissal of an appeal in circumstances where, despite apparent error, the judgment below did not result in a substantial miscarriage of justice. Thus, in HTW Valuers (Central Qld) Pty Ltd v Astonland Pty Ltd (2004) 217 CLR 640 at [50], the Court dismissed an appeal with respect to damages suffered as a result of negligent advice and misleading and deceptive conduct, with the following statement:
"Let it be assumed in favour of the defendant that the true value [of the property] in April 1997 was above $130,000 … . The verdict of the trial judge, on the present approach, can only be upheld if the true value in April 1997 was about $130,000. But even if it was above that figure, so that that component in the award was wrong, the total sum for which the trial judge ordered judgment has not been shown to be so wrong as to have caused an injustice to the defendant. That is particularly so when it is remembered that in certain other respects the trial judge appears to have made errors in calculating damages which are adverse to the plaintiff."