Within each census metropolitan area, the census non-institutional population and deaths were grouped into neighbourhood income quintiles based on census tract percentage of population below Statistic Canada's low-income cut-offs, which vary by family size and are Canada's unofficial "poverty lines."

The cut-offs are regularly adjusted for inflation so they are now much higher than their US counterparts.

The percentage poor in each quintile was fairly stable from 1971 to 1991�but it increased especially in the poorer quintiles from 1991 to 1996, which coincided with a period of increasing unemployment and greater income inequality in Canada.

Note that relative rather than absolute income was used to define the quintiles�so fifths of the population ranked by income were compared, regardless of how income distribution changed over time.