YOU wouldn't expect a Home Secretary to be deeply troubled by a rise in the price of cannabis. After all, the current incumbent could move to allay any resultant family disquiet by slipping his son a few more pennies in pocket-money.
However, the rising cost is not in marijuana's street value, but in the price being borne by a criminal justice system that has witnessed a ninefold increase over the last decade in the number of cautions issued for possession of the drug.
The latest figures (for 1995) reveal that more than 40,000 cautions were made for basic unlawful possession - that is, possession without intent to supply.
The Audit Office estimates that a caution costs in the region of pounds 1,200 - a startling figure made more comprehensible by the fact that each caution involves a minimum of three police officers and associated administration.
It hardly requires Carol Vorderman to do the sums: it's costing around pounds 48m a year to caution people for personal possession of cannabis. Actual prosecutions for possession, and the whole spectre of dealing, aren't even part of this conundrum.
But is this pounds 48m money well spent? Should decriminalisation of cannabis just happen to remove the illegality of personal possession, what could Jack Straw, let loose with pounds 48m, fill his shopping trolley with?
Feeling altruistic, he may hand the money over to David Blunkett, who could buy five shiny new secondary schools and seven primary schools - serving 6,000 children in all. A whip-round for another two million quid, and he could get Frank Dobson a district general hospital.
Or if he was suffering from short-term memory loss - maybe William had made pudding - Jack might forget his past as a paid-up member of parliamentary Labour CND and lend George Robertson the cash to procure four Trident missiles (warheads not included).
Should he want to keep the money for the Home Office, he could use the pounds 48m to put 2,826 bobbies on the beat. Or maybe, as a treat for the staff, he could buy every police officer a 32-year subscription to Freemasonry Today.
Straw - of which he could purchase 72 million bales - might splash out closer to home on a personal passion. The moolah would acquire the current Blackburn Rovers squad - a snip at pounds 21.5m - and leave enough change to bring Shearer, Le Saux and Berg back to Ewood Park. Move over, Walker, there would truly be a new "Uncle Jack" in town.
If none of these appealed, he could always take advantage of the decriminalised status of cannabis: pounds 48m could get Jack 16 tonnes of hashish, about 32 cubic metres in dimension, which funnily enough would fit snugly into The Body centrepiece of the Millennium Dome. Now there's a cautionary tale.