Cancellation of the mandatory long-form census - background and impact
"I want to take this opportunity to comment on a technical statistical issue which has become the subject of media discussion ... the question of whether a voluntary survey can become a substitute for a mandatory census. It can not."
Aside from data suppression, Statistics Canada notes in the NHS User Guide that the data may not be comparable to the previous (2006) long-form Census:
"Caution must be exercised when NHS estimates are compared with estimates produced from the 2006 Census long form, especially when the analysis involves small geographies. Users are asked to use the NHS's main quality indicator, the global non-response rate (see Section 6.3), in assessing the quality of the NHS estimates and determining the extent to which the estimates can be compared with the estimates from the 2006 Census long form. Users are also asked to read any quality notes that may be included in dissemination products. "
- The release of immigration data from the NHS announced that the largest source of immigrants to Canada in the past five years was the Philippines - a finding at odds with the immigration records collected by Citizenship and Immigration Canada. Statistics Canada acknowledged:
"This result was not in line with administrative data from the Department of Citizenship and Immigration Canada which provides the number of recent immigrants by their country of birth settling in Canada each year. A number of factors could explain this difference, such as the effects of sampling, response patterns, and under or over estimation of certain groups of recent immigrants in the NHS."
- In the Income Reference Guide, Statistics Canada notes:
"Given the sensitivity of most income indicators to such methodological differences, users should use caution when comparing income estimates from the NHS to other household income surveys, administrative data or 2006 Census data or earlier censuses."
Some researchers have questioned the reliability of the NHS, calling for the income data to be withdrawn. These SSHRC-funded researchers compared income data from the NHS to tax-filer data from the Canada Revenue Agency, and declared that:
"The income data in the National Household Survey is not valid. It should not be used or cited. It should be withdrawn. The 2016 census should be restored to the non-politicized, non-partisan scientific methodology that existed prior to the flawed 2011 National Household Survey."