ABSTRACT
In the last chapter we discussed the many ways in which one economic variable may affect another. The economic system as it moves through time is a network of interconnections by which one variable affects another, which in turn affects another, which in turn affects another, and so on without cessation. In this process it will often happen not only that one variable (say X) will indirectly or directly affect another variable (say 7), but also that this other variable (Y) will itself indirectly or directly affect the first variable (X).
