What Do Supply and Demand Curves Really Tell Us? Not Very Much
It is commonly held that prices of goods and services can be produced by means of supply and demand curves. These curves describe the relationship between the prices and the quantity of goods supplied and demanded.
Within the framework of supply-demand curves, an increase in the price of a good is associated with a fall in the quantity demanded and an increase in the quantity supplied. Conversely, a decline in the price of a good is associated with an increase in the quantity demanded and in a decline in the quantity supplied.