Statistical data sources
Apparent consumption is a figure that is derived from
production, plus imports less export. Real consumption also uses these
parameters but includes stock levels.
The only source of import and
export statistics is that collected by customs authorities. It is widely
known that the base data reported does have significant flaws in it.
For example the only legal requirement in the UK is to report the value
of goods moving in and out of the country therefore although parameters
of volume or weight may be reported they cannot be relied upon.
International trade statistics only record the last country of dispatch
therefore the figures reported do not necessarily report only goods
manufactured in a given country. There is no remedy to this latter
Because of the known reporting errors in respect of
value/volume/weight, it is possible to apply a rational which cross
compares these values and then by applying a set of assumptions as
regards average density, thickness and value it is possible to arrive at
a set of import figures (exports are more likely to be recorded
accurately) that more accurately reflect the true position.
Statistical reporting of this type is not a statement of
fact but rather a resemblance of the true position and the real value
comes when looking at long term trends.