Books Reviewed Galor, Oded. Discrete Dynamical Systems.

Consider a demand-supply system in which the demand for a product depends on the current price in the market but its supply depends on the price at some previous point in time. In such a system, the current equilibrium (market-clearing) price will typically depend on past equilibrium prices. This dependence may be formally captured by writing down a functional relationship (time map) between the current and past equilibrium prices. Such a relationship is called a difference equation if time is measured in discrete integer units (periods).
If it so happens that the current equilibrium price depends only on the equilibrium
price in the previous period, then the time map is characterized by a first-order difference equation. If the functional relationship is linear, it is called a linear difference equation.
If the functional relationship jointly involves more than one variable (suppose the current equilibrium price and capacity are jointly determined), then it is labeled as multidimensional difference equation system.