This paper reviews the extensive theoretical and empirical literature on currency substitution. After discussing the ambiguity surrounding the definition of currency substitution, the paper illustrates the causes of substitutability of different currencies using a cash-in-advance model and a...

We explore the properties of velocity in a model where agents are required by law to use money to pay taxes, but not for any other private purchases. The model is applied to Brazil between 1975 and 1990. We show that the model mimics consumption velocity very closely during the high-inflation years.