The Gold Standard

The economic gold standard is the half ounce packet of tobacco.  In days past this was Old Holborn, now it is Golden Virginia.

The tobacco half ounce has always been the bedrock medium of economic activity, and this has not changed in the force of the influx of heroin.  For whilst in some locations there may be more economic activity in drugs as measured in GBP, the price of a ten quid bag of smack is largely tied to tobacco rather than natural £10 GBP notes.

The reason for this is that tobacco is a legal item and there are vastly more smokers than heroin users.  As a result, tobacco is easily and conveniently used as the medium of exchange, even by non-smokers.

The illegality of heroin, conversely, limits its availability and it is not used as an economic medium by non-drug users.  Hence a prison may contain a greater GBP value of heroin over tobacco, whilst the latter remains the general medium of currency.

Prisons holding young prisoners forbid tobacco.  I'm fascinated to know what, then, is the bedrock of their economy   How does this affect their socio-economic structures?