On testing Easterlin's hypothesis using relative cohort size as a proxy for relative income: an analysis of Canadian...

"Measures of Canadian fertility (total fertility rate and fifteen-year age-specific fertility rate...) and relative cohort size (population aged 30-64 years divided by population aged 15-29 years) show a close co-movement between 1940 and 1976 but record a marked departure since then. The application of cointegration techniques to these series (1921-1988) shows that they do not form an equilibrium relationship even over the period 1940-1976. Contrary to the expected relationship between relative cohort size and relative income, income data by age groups show that there is no tight relationship between them. The absence of an equilibrium relationship between relative cohort size and fertility, therefore, does not necessarily imply that Easterlin's hypothesis is false."