This page contains a Flash digital edition of a book.

Implications for Data Availability For the first release of the NHS, about one in four of

the more than 5,000 Census subdivisions (municipalities, towns, villages, etc.) had a GNR rate of 50% or more, and therefore data for these areas were suppressed. However, the suppressed areas were very small in size, mostly located in rural and small-town areas, and accounted for only 3.4% of the total Canadian population. Of more concern than the suppression of data for small

Census subdivisions is the impact on data availability at lower geographic levels, in particular, Census tracts and DAs that are the building blocks for trade areas. Statistics Canada has indicated that data will be published at the Census-tract level, although the degree of suppression is not yet known. In view of the fact that the average size of a Census tract is about 4,500 people and they are found in more highly urbanized areas where a non-response follow-up was more often done, a relatively lower level of data suppression is expected. Statistics Canada has not yet indicated whether it will

publish any data at the DA level. Overall, there are approximately 55,000 DAs with an average population of 600. Based on the collection follow-up strategy and the published response rates for Census subdivisions, it can be expected that many, if not most, DAs in rural and small towns would not meet the 50% GNR cutoff for publication. Moreover, even in more urbanized areas, non-response rates are likely lower in the large, diverse urban areas where follow-up occurred and higher in small, more homogeneous urban areas. As a result, there may be considerable suppression in some urban areas.

Over and above the complete suppression of data for

geographic areas that do not meet the GNR threshold of 50%, questions exist about the amount of detail that will be provided for certain geographic areas. For example, in the first release of the NHS in May 2013, detailed cross tabulations were provided for all provinces and territories and for the 33 Census Metropolitan Areas of Canada. However, only much more limited data were published for municipalities, regardless of size. At the time of this writing, it was not known what other data may be published at a municipal level.

Conclusion Data based on the NHS must be used cautiously.

Users will need to pay much more attention as data- quality documentation becomes available from Statistics Canada and data users in general. Certainly, there should be increased caution about smaller geographic areas and population groups. However, even for larger geographic areas, there is the

potential impact of unknown response bias. This will be particularly important in looking at comparisons over time when the response bias may artificially show a change in trend or perhaps mask a true change that has occurred. Users need to guard against what might be a natural tendency to accept trendlines with historical patterns and question those that show a change in pattern. In some cases, there has been some real change when none was observed; in others, there may be observed changes that result from bias in the data. Unfortunately, it will be more difficult than ever to know if an observed trend is real or an artifact of the response patterns.

Dr. Douglas Norris, one of Canada’s leading experts on the Census, is currently Senior Vice

President and Chief Demographer at Environics Analytics. He joined EA in 2006 after nearly 30 years with Statistics Canada, where he served as Director General of Social and Demographic Statistics. Currently, he assists companies, government agencies and not-for-profit organizations in using census and other statistical information for planning and marketing projects. He can be reached at


42 4


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54