For a parcel 7.091

For the letter packets under 1 ounce in weight, for those between 1
ounce and 4 ounces in weight, for the halfpenny packets and for the
postcards, the estimated average cost will be approximately the actual
cost per packet; but in the case of letter packets over 4 ounces in
weight and newspaper packets, the variations in weight and convenience
of handling are considerable, and there will be an appreciable
variation for individual packets above and below the estimated average
cost. The cost will vary with the weight and size (but not
proportionately), and the deviation will be greatest in the case of the
heavier packets, since with both these classes the average weight of the
great bulk of the packets is less than the general average. Of all
letter packets, postcards, halfpenny packets and newspapers, the number
exceeding 4 ounces in weight forms less than 10 per cent. With so small
a proportion of heavy packets the result may be taken as almost exact in
the case of the lighter packets. It is not in excess of the actual cost,
because the calculation, taken as a whole, is biassed in favour of the
heavier packets.

The resultant figures are figures of average cost. They represent the
cost of those packets in each class in respect of which the average
amount of service is performed, and not exceptional cases, as when
packets travel over very long distances, or when a packet is redirected
or returned to the sender, in which latter cases obviously double the
normal service is performed.

The calculation is approximate in that at certain points it has been
necessary to frame estimates on imperfect data. This is inevitable in
dealing with a service conducted over a large area and under diverse
conditions.[624] In general the manner in which the result is affected
by the use of imperfect data has been indicated. These variations have
been borne in mind throughout, and, as their effects are produced in
varying directions, the combined effect is not such as to invalidate the
results arrived at.

The result suggests the following conclusions:--

(1) That no class of packet sent at the letter rate of postage
involves a loss to revenue;

(2) That there is a large profit on ordinary light letters;

(3) That in the case of packets of the weight of about 4 ounces the
profit is less, but is still appreciable;

(4) That there is a considerable profit on