(D) MORE THAN ONE VICTIM
There is one particular problem of causation which arises where there are a number of potential claimants. In such circumstances it will sometimes be very difficult, if not impossible, to show that the benefit obtained by the defendant derived from the commission of a wrong against a particular claimant. For example, if the defendant owns a factory which discharges pollutants into the air, causing a nuisance to nearby residents, but no loss to them, and the defendant saved ?100,000 as a result of failing to install the necessary devices which would have drastically reduced pollution, what should be the measure of the claimants’ remedy? This will depend on who sues the defendant. If only one resident sues, but ten have been affected, should the one person who sues recover the full amount which the defendant saved, or only a proportion? If the claimant is awarded only a proportion, how should this be ascertained?
Where it is possible to apportion the defendant’s gain amongst all potential claimants, this is the proper course to take. So, for example, in Jaggard v Sawyer the defendant had breached a covenant which had been made with nine other people. Only one of these sued the defendant and the remedy which was awarded was ascertained by identifying the full amount which the defendant would have been liable to pay if all the victims had sued and then one ninth of this amount was allocated to the claimant. But this was an easy case, since the number of potential claimants was readily ascertained. In other cases it might be very difficult to predict how many people had been affected by the defendant’s wrong, so it would not be possible to ascertain how the benefit obtained by the defendant as a result of the commission of the wrong should be allocated to any particular claimant who sued the defendant. In such circumstances there are only two possible solutions. The first is that the claimant should be denied gain-based remedies completely. For this reason, the Court of Appeal has held that exemplary damages will not be awarded where there are a large number of claimants.143 Alternatively, the defendant should be required to disgorge all benefits to the claimant who successfully sues first. Such an approach has been recommended by the Law Commission as appropriate where the defendant is liable to pay exemplary damages. Since the fundamental principle of the law of restitution for wrongs is that the defendant should not profit from the commission of the wrong, this approach would also be appropriate in the context of restitutionary remedies, where it is not possible to apportion the defendant’s gain between different claimants.
-  Aggravated, Exemplary and Restitutionary Damages (Law Com No 247, 1997), 50-1. There is noproblem where there is more than one defendant, since each defendant will simply be liable to disgorge thebenefit which he or she had obtained as a result of the commission of the wrong. See ibid, 49.
-   1 WLR 269. 143 AB v South West Water Services Ltd  QB 507.
-  Aggravated, Exemplary and Restitutionary Damages (Law Com No 247, 1997), 189.