["Nations and Nationalism, Volume 26, Issue 4, Page 923-942, October 2020. ", "\nAbstract\nThe purpose of this research was to investigate the impact of immigration on local ethnic groups' demographic weight (DW) by presenting a case study. In this study, the ethnic French Canadians (EFC), a group that makes up the majority of the Province of Quebec, were studied to evaluate the impact of immigration on their DW. It was found that EFC transitioned from a DW of 79% in 1971 to a DW of 64.5% in 2014; projections predict that EFC would decrease to a DW of 45% in 2050. Moreover, 45 immigration rate scenarios and total fertility rates were projected; it was found that immigration level and fertility level could be jointly classified into three categories related to their effect on ethno‐demographic decrease; one of these categories may help suggest a quantitative definition for the concept of mass immigration.\n"]