From the CBC news:
A new study has estimated that high school dropouts cost Canada’s social assistance and criminal justice programs just over $1.3 billion annually.
The study, carried out by Simon Fraser University researcher Olena Hankivsky and funded by the Canada Council on Learning, found that the Canadian government could save $963 million on social assistance if every high school dropout graduated.
Dropouts also account for $300 million in increased criminal justice spending, the report found.
The full report is available here in .pdf format.