OTTAWA -- The illegal production and consumption of non-medical cannabis was worth about $3.3 billion in 2016, according a Statistics Canada analysis of the underground economy.

The agency generally hasn't included illegal drugs and prostitution in the underground economy, but it has been providing more cannabis-related data ahead of Oct. 17, when recreational use of pot becomes legal in Canada.

The agency estimated underground economic activity totalled $51.6 billion or 2.5 per cent of Canadian gross domestic product in 2016.

It said the underground economy increased 3.5 per cent from 2015 to 2016, topping the 2.0 per cent growth in total economy. With price changes removed, the underground economy increased 1.8 per cent, while the total economy was up 1.4 per cent.

Statistics Canada noted the underground economy as a proportion of GDP has been relatively stable, reaching a high of 2.7 per cent in 1994 and a low of 2.2 per cent in 2000.

It said three industries accounted for more than half of the underground economy in 2016: residential construction (26.6 per cent), retail trade (13.5 per cent) and accommodation and food services (12.1 per cent).

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