Sin Tax indexed to Sin Cost

This may very well be baked somewhere as it was probably the original intention of the sin tax but ... it seems to me that no government can resist channeling sin tax revenue into the "general revenue" pot. Not only does this not compensate society for the costs of these "sins", governments become so reliant on these revenue streams, their budgets are constructed with the hope that these "sins" continue.

My solution is to index the sin tax to the actual cost of the sin. So, for example, if it is found that alcohol related illness is costing the state X dollars per year (medical, policing costs) and Y litres of alcohol is consumed per year, then the tax is X/Y dollars per litre. A law would have to be created to ensure that this money goes directly into the appropriate budget (Health care, Law enforcement).

This way if the government wants to fund a new stadium or freeway they will have to come up with a legitimate business model rather than just snatch the money from the Health Care budget.

Sure some governments will still try to cheat and put this money into general coffers but if the implentation of the sin tax is clearly defined in the first place, the watchdogs would be all over them as soon as they step out of line.