As the large generations of the 1950s and 60s have entered adulthood, when participation in the workforce is highest, the proportion of people in this age range has grown (from 62% in 1980 to 74% in 2000). With only a marginal decrease in the proportion of older workers, these gains have been a result of the relatively large decrease in the youth labour force (from 26% in 1980 to 16% in 2000).

The decline in the proportion of youth is not simply a relative phenomenon. In the early 1990s, the number of 15 to 24 year old workers decreased to fewer than 2.5 million; in 1980 it was over 3 million. Certainly the sharp decline in fertility rate in the 1960s and 1970s, to well below the generation replacement rate in the first half of the 1970s, is having an impact. Staying in school longer, especially among older youth (20-24 years) has also been a significant factor.

As a consequence of these trends, the average age of the labour force has risen from 32 years in 1971 to 37 in 1990, and is likely to be over 40 years by 2005.

Because of changes in fertility rate and shifts in immigration, the composition of the youth labour force cohorts is increasingly diverse: the proportion of members of visible minorities is growing rapidly. In this group, the proportion of youth under 15 years is larger than in the general population.