This publication presents the results of a study undertaken to measure the economic costs of students who drop out of secondary school in Canada and summarizes the social and economic costs of dropping out. The primary objectives of the report are to raise awareness of these costs among the business community and to motivate all stakeholders to invest in the labor force of the future. The economic prosperity of the nation as a whole, employment rates, and the climbing dropout rate in Canada during the 1980s, when over one-third of Canada's youths were not graduating from secondary school, are considered in terms of education's importance. The myth of the over-educated Canadian is also discussed. The cost to Canadian society over the working lifetime of the nearly 137,000 secondary school dropouts who should have graduated in 1989 is $4 billion in present-value terms. Each individual male dropout will lose nearly $129,000 in today's dollars over his working lifetime, while the female dropout forfeits $107,000. As an investment vehicle, education has a higher rate of return than almost any alternative investment project. The rate of return to society of investing in secondary school education is 19.0 percent for males and 17.8 percent for females. Canada could save $26 billion if the dropout rate was reduced from 34 percent to 10 percent by the year 2000. Any initiative that encourages students to complete secondary school can have a major positive impact on the future economic well-being and prosperity of both the individual student and Canada as a whole. Includes 15 notes and 14 charts/exhibits/tables. (JB)