In the 30 years since Quebec passed its language law, Bill 101, francophones have made substantial gains in income and in ownership of the economy, according to a new study by the C.D. Howe Institute.

The study shows the economic benefits of knowing French in Quebec have increased steadily since the 1960s, while the benefits of knowing English have declined.

Economists Francois Vaillancourt and Dominique Lemay, along with McGill University law student Luc Vaillancourt, produced the study, titled "Laggards No More: The Changed Socioeconomic Status of Francophones in Quebec."

They said that the ability to speak both English and French has increased the earnings of anglophone men since 1980, with the same true for anglophone women since 1990.

The benefits of being bilingual also have been positive for francophone men and women, the authors wrote.

"The healthy state of the French language in Quebec is also evident in the impressive growth in ownership of Quebec's economy by francophone firms, from 47 per cent to 67 per cent since the early 1960s."

Foreign ownership declined by 26 per cent over the same period, while anglophone Canadian ownership declined by 44 per cent.

The authors of the report studied census data to calculate the changes in income by language group and by sex. They screened out the effects on income of factors such as level of education, years of experience and length of time worked.

They found that in 1970, bilingual francophones trailed bilingual anglophones, making about $7,360 on average, compared to $8,940 for anglophones.

By 2000, they were making just slightly more than anglophones, $38,850 compared to $38,745.

To explain some of the changes, the authors of the study point out that there was a significant departure of anglophones from Quebec after Bill 101 was passed. They also note that the public sector hired a lot of francophones after the province's Quiet Revolution.

"In turn, private-sector, francophone-owned firms grew by providing services in French to the public sector."

The report argues that learning a second language in elementary schools is important, given the "plasticity" of younger brains and the obvious benefits of bilingualism.