Born in 1946, Sager has taught at the University of Victoria and Simon Fraser University. His books include:

Seafaring Labour: The Merchant Marine of Atlantic Canada, 1820-1914 (McGill-Queen's University Press, 1989)

Maritime Capital (McGill-Queen's University Press, 1990)

Ships and Memories: Merchant Seafarers in Canada's Age of Steam (UBC Press, 1993)

The Professor and the Plumber: Conversations About Equality and Inequality (FriesenPress, 2021). With illustrations by Hanna Melin.

Co-author of:

Unwilling Idlers: The Urban Unemployed and Their Families in Late Victorian Canada. (University of Toronto Press, 1998). With Peter Baskerville.

Household Counts: Canadian Households and Families in 1901 (University of Toronto Press, 2006). With Peter Baskerville.

The Professor and the Plumber: Conversations About Equality and Inequality (FriesenPress, 2021) $38.99 978-1039105560

Inequality in Canada: The History and Politics of an Idea (McGill-Queen’s University Press, 2021) $43.95 978-0-22800-580-3

[BCBW 2023] "Maritime"

Review of the author's work by BC Studies:
Unwilling Idlers: The Urban Unemployed and Their Families in Late Victorian Canada