The cost of high-grade cannabis could drop to around $70 per ounce from today’s rate of around $350 per ounce, if California legalizes over-21 possession and consumption of the plant, a leading think tank disclosed today. “Altered State? Assessing How Marijuana Legalization in California Could Influence Marijuana Consumption and Public Budgets” by the Rand Corporation finds that most of today’s pot costs are actually risks to growers, distributors, and sellers who face arrest and jail time. Lifting that risk, along with automation, and economies of scale would cause about an 80 percent drop in the price of sensimilla. The study could not say what would happen to rates of consumption with certainty, but use could double from 7 to 14 percent of the adult population.