The primary source is Statistics Canada's Labour Force Survey.
This survey is conducted using a sample of respondents and data may be suppressed for reasons of confidentiality or data quality, but it is the most inclusive, timely and unbiased source of wage data by occupational group.
When the Labour Force Survey data is not available, other sources are considered, including:
Employment and Social Development Canada program data such as Employment Insurance program survey data
Provincial and territorial surveys and administrative data
Other organizations administrative data, such as the Canadian Institute for Health Information and the Canadian Medical Association, etc.
What is the meaning of low, median and high wages?
The low wage, in most cases, corresponds to the 10th percentile :
For example, if the low wage is $12.00/hour, this means that 10% of the workers in the occupation earn $12.00/hour or less.
The median wage is the indicator of the prevailing wage for each occupation.
The median wage is the middle point of the wage distribution, when wages are ranked in numerical order.
The high wage, in most cases, corresponds to the 90th percentile.
For example, if the high wage is $40.00/hour, this means that 90% of the workers in the occupation earn $40.00/hour or less.