This table provides information on the number of years in low income over an eight-year period among Canadian tax filers. The years in low-income may or may not be adjacent to each other. For example, during an eight-year period, a tax filer who was in low income for two years could be in low income in the first year and the third year. Low income statistics derived from administrative data can differ from those derived from survey data due to a number of factors. For example, the census family is used as the unit of analysis instead of the household; family composition is derived from administrative sources and not a household roster; aboriginals on reserve, temporary residents, military personnel in barracks and persons living in collectives who file taxes are included in administrative data but not in survey data. While the levels of low income can differ, the broad groups affected by low income and broad trends over time are similar to those found in survey sources.
Two types of low income measure (LIM) thresholds are used in this table. The variable LIM threshold is re-estimated each year while the fixed LIM threshold is based on median income in 2002 and is adjusted by the all-items Consumer Price Index to account for inflation in other years. For a discussion of the fixed LIM threshold, see Xuelin Zhang (2010): “Low Income Measurement in Canada: What Do Different Lines and Indexes Tell Us?”. Income Research Paper Series, Catalogue no. 75F0002M -- No. 003, Statistics Canada, Ottawa, Ontario.
The low income measure (LIM) is used to identify low income tax filers. The LIM threshold is calculated as half of the median of the adjusted income of all tax filers and their family members. The adjustment is made by dividing the after-tax income by the square root of the census family size. Census family is the only family unit available in the Longitudinal Administrative Databank. Details of the calculation can be found in Murphy, Brian, X. Zhang and C. Dionne. (2010) “Revising Statistics Canada’s Low Income Measure (LIM)”, Income Research Paper Series, Catalogue No. 75F0002M – No. 004, Statistics Canada, Ottawa, Ontario.
The tables ordered were produced using data from the Longitudinal Administrative Databank (LAD). This data source is mainly based on a 20% sample of the T1 Family File (T1FF). In order to maximize the efficiency of the longitudinal aspect of the LAD data, some additional geography processing steps are applied to LAD data. This difference in the geography processing, in addition to differences based on the fact that LAD is a 20% sample of T1FF, can lead to differences in geographical coverage between these two data sources, especially for lower levels of geography such as census subdivisions (CSDs). Hence, a user should expect, on occasion, some notable differences in CSD tax filer counts when comparing data from these sources.