## Calculating effect of a price ceiling - example

Assume a linear demand function of the form:

**Qd = 85 - 5P**

and a linear supply curve of the form:

**Qs = -20 + 10P**

Using these demand and supply functions, answer the following questions. Once you have had a go at the questions, follow the link below to compare your answers.

- Calculate the quantities demanded and supplied for prices from $1 - $15.
- Plot these figures to give the demand and supply curves for the product.
- Using simultaneous equations, calculate the equilibrium price and output.
- The government then imposes a price ceiling of $4 on the market. Show this on the diagram.
- Calculate the excess demand as a result of this price ceiling.
- Calculate the level of consumer expenditure:
- before the price ceiling was imposed
- after the price ceiling was imposed