I would like to see amendments to the Misuse of Drugs Act 1971 and the Psychoactive Substances Act 2016 so that any person caught with 1 gram or less of a class A, B or C drug cannot be prosecuted.
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I think this would:
1) Lower the cost of policing. The police might detain, arrest and take fewer people to custody. There should also be fewer court procedures or formal Out of Court Disposals where administration and interviewing costs apply.
2) Stop people getting a criminal record for possessing a small amount of a controlled substance. This could allow them more employment opportunities to pay a higher rate tax.