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Survey design

SLID is a household surveys that covers all individuals in Canada, excluding residents of the Yukon, the Northwest Territories and Nunavut, residents of institutions and persons living on Indian reserves or in military barracks.

The SLID sample is composed of two panels. Each panel consists of roughly 15,000 households and about 30,000 adults, and is surveyed for a period of six consecutive years. A new panel is introduced every three years, so two panels always overlap.

Figure 1. Overlapping design of SLID sample

A preliminary interview takes place at the beginning of each panel to collect background information. From then on, each of the six years has a split-interview format with the first interview occurring in January and the second in May. Questions in both interviews refer to the previous calendar year. In January, interviewers collect information regarding respondents' labour market experiences, educational activity and family relationships. The demographic characteristics of family and household members represent a snapshot of the population as of the end of each calendar year.

In May, interviewers collect information on income to take advantage of income tax time when respondents are more familiar with their tax returns. Over 80 percent of respondents give us their permission to consult their income tax file, and thereby avoid the May income interview.