Despite vast progress in school enrolment over the past few decades, Quebec continues to fare poorly when it comes to dropping out of school, particularly among boys. According to 2021 Census data, 12.1% of young men aged 25 to 34 in Quebec had no diploma or qualification, compared to 7.4% of women. The high school graduation rate for boys is lower in Quebec than in any other Canadian province. Since education brings many benefits, both on an individual and societal level, this under-education of boys is a cause for concern. A high drop-out rate represents a substantial loss of productivity potential, and is associated with greater pressure on public finances, as less-skilled and less-educated individuals contribute less to tax revenues on average, and receive more in government transfers. In this study, the authors assess the extent to which men's and women's educational attainment explains differences in labor market attachment, employment earnings, government transfers and income taxes paid, and what employment earnings, taxes paid and government transfers could be achieved by raising boys' high school graduation rates to those of girls. They then propose projections from 2021 to 2066 to illustrate how the population of men and women in Quebec, and its distribution between different levels of education, are likely to change over the next few years. Their analyses make it possible to assess the socio-economic benefits of catching up on boys' graduation rates, an essential element in any benefit-cost analysis.