When rival firms issue long-term debt, their product market behavior i
s driven by strategic considerations that would not be present if the
firms had no debt or if their debt was short term. It is shown that wi
th limited liability, a firm's behavior in product market competition
can be strongly affected by its accumulated profits. In markets where
firms choose output in every period, the higher is the firm's profit i
n a given period, the less aggressive it will be in the subsequent per
iods. Thus, by issuing long-term debt rival firms may induce collusive
behavior over some length of time. Furthermore, the path of equilibri
um prices and the degree of price fluctuations may be entirely differe
nt depending on the structure of the firms' debt.