If you want to make both head and tail of the scary drug numbers that were poured across the front page of your Herald this morning, a so called "Drug Harm Index" that is "more or or less explicitly a public relations tool for police," then head to Russell Brown's post this morning (and the mostly sane comments that follow the post). "Spectacular but useless" is one of his nicer descriptions for an index of the costs of drug harms that ascribes all the the costs incurred due to prohibition (i.e. cost of jail, courts, policing) to the costs of the drugs themselves. The words "falsely inflated" are two more that spring to mind as descriptions of this bogus "index."
UPDATE 2: Eric Crampton, another real economist, notes that Des O'Dea, one of the authors of this new study, was also the author of a cost-benefit analysis of smoking which Crampton tore apart here. "I wonder," he wonders, "if the same errors repeat themselves...."