In fatal accident cases, the principle laid down is that the claim should be assessed after deduction of the estimated sum to represent the victim’s probable living expenses following a fatal accident, during the lost years, but it gave little guidance.
There were differing assessments by the courts when calculating the lost years since the two leading authorities, but guidance was provided by the CA in a combined judgement in Harris v Empress Motors Ltd and Cole v Crown Poultry Packers Ltd  1 WLR 212.
The general principle is in 3 stages;
1. Assess the living expenses of the deceased, (the ingredients of the expenses are the same if the victim is old, young, single or married);
2. The sum to be deducted as living expenses is the proportion of the victim’s net earnings that he spends to maintain himself at the standard of life appropriate to his case;
3. Any sums expended to maintain or benefit others do not form part of the victim’s living expenses and are not to be deducted from the net earnings.
The assessment, following a fatal accident, is similar to the calculation under the Fatal Accident Act. However, where there is a shared benefit eg. rent, utility bills, television licence or running a car, which are undoubtedly living expenses a deduction will be made referable to each persons share. Thus the victim’s living expenses shall be deducted save that sums expended for the joint benefit of the victim and others should only be regarded as the victim’s living expenses to the extent of his share of the joint expenditure.
Under a Fatal accident claim no deduction is made for the shared living expenses as one cannot drive half a car or live in half a house as the person is dependent on the whole benefit. In contrast, the whole cost of the shared expenses should not be deductible from the victim’s living expenses as this in incompatible with the third principle, above.
As the number of persons provided for out of the victim’s net earnings increase, so must the amount to be allocated as being his share of those items fall. Thus in a fatal accident claim, a household of four will result in one-quarter of the cost of joint items to be deducted. In practice the total deductions may not be that much greater than a dependency claim under the Fatal Accident Act but by way of a general observation, the proportion will be greater than the percentage under the Fatal Accident Act dependency claim. One-third is usually deducted in a fatal accident claim in a husband and wife case and one-quarter if there are children, (typical husband and wife with two children).