Pierre Fortin's analysis of the causes of the increase in Canada's debt-to-
output ratio is reconsidered. We find that the analysis hinges upon a numbe
r of supplementary decisions, and that reasonable choices give rise to resu
lts strikingly different from those obtained by Fortin. We also extend Fort
in's analysis to examine the causes of debt accumulation by level of govern
ment. This exercise shows that the causes of debt accumulation are very dif
ferent at the federal and subnational levels.