In a monetary economy of production, Say's law is invalid for several reasons. On the basis of some of these refutations (Schmitt, 1984; Renaud, 2000), it is possible to state that the revenues generated by the production process are structurally lower than the supply price of production. We study here the dynamics of such an economy and obtain two main results. First, the long-term debt level of this economy has to increase during a growth phase to enable demand to grow at the same pace as supply. Secondly, due to the repayment of this debt, the gap between supply and net revenues generated by the production process widens along a growth phase.