Source Article

Quantum of Damages
NB figures in brackets are a reference to paragraph numbers in The Law of Damages

The standard of proof - balance of probabilities
In Murphy v Stone Wallwork (Charlton) Ltd [1969] 2 All ER 949 at 952, [1969] 1 WLR 1023, HL, Lord Pearce said that:

"...the assessment of damages for the future is necessarily compounded of prophecy and calculation. The court must do the best it can to reach what seems to be the right figure on a reasonable balance of the probabilities, avoiding undue optimism and undue pessimism."

Although this statement was made in the context of future loss, the standard of proof is the same regardless of the type of loss suffered.

The Certainty Issue
Certainty has been used to describe the standard of proof for centuries: see for example Ratcliffe v Evans [1892] 2 QB 524, CA (6.11) and The Conqueror 166 U.S. 110 (1897). The trouble with certainty however is that it is ambiguous and suggests that mathematical accuracy is required in the assessment/quantum of damages. When it is argued that damages are impossible to assess it means impossible to assess with certainty/mathematical accuracy. The impossibility argument is however inconsistent with the Chaplin v Hicks/best estimate rule.
Certainty is however capable of being construed in a manner which is consistent with the ordinary standard of proof. In Mallett v. McMonagle [1970] AC 166; [1969] 2 All ER 178, at 190 HL Lord Diplock said that:
" in making an assessment of damages ..... a court decides on the balance of probabilities. Anything that is more probable than not it treats as certain."
Amount/quantum/how much?
The amount of compensation/damages is governed by the underlying/but for principle (1.2-1.3). The claimant is entitled to be placed (so far as money can do it and within reason) in the position he would (on balance of probabilities) have been in but for the breach (sometimes referred to as the measure of damages (6.3)).
The better evidence rule. Expressed differently, the claimant is entitled to recover the amount which he has, on the balance of probabilities, suffered as a result of the breach, that is, the amount which can be reasonably inferred/assessed from the evidence (6.4). The amount will therefore depend on the evidence adduced and the credibility/weight thereof (6.13). The effect is the better evidence rule - the better the evidence the more reliable, in terms of certainty/accuracy, the assessment will be. In R v Kajala (1982) 75 Cr App R 149 Ackner LJ stated (at 152) that:
"The old rule, that a party must produce the best evidence that the nature of the case will allow, and that any less good evidence is to be excluded, has gone by the board long ago. The only remaining instance of it is that, if an original document is available on one’s hands, one must produce it; that one cannot give secondary evidence by producing a copy. Nowadays we do not confine ourselves to the best evidence. We admit all relevant evidence. The goodness or badness of it goes only to weight, and not to admissibility. Garton v. Hunter ([1969] 1 All ER 451, [1969] 2 QB 37), per Lord Denning. See also Archbold, Criminal Pleading, Evidence and Practice ((40th edn, 1979) para 1001)."
Where better or precise (quantum) evidence is obtainable but not adduced the court has a number of options.
Copyright Stewart Dunn except:
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