Statistics Canada forecasts Canadians could spend more than $1 billion on legal cannabis between October and December this year once marijuana for adult use is legalized on Oct. 17.
The agency estimates that the amount spent on legal pot during the fourth quarter could range between $816 million and $1.02 billion.
It added that purchases of illicit cannabis during the same period could be between $254 million and $317 million, or 24 per cent of the total market.
Statistics Canada estimates there will be 5.4 million people who want to purchase legal cannabis in the fourth quarter.
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Still, the agency estimates that 1.7 million will likely continue to buy illegal pot during the three-month period.
The estimates were derived using census population data and statistics from the quarterly National Cannabis Survey, an online questionnaire.