The interaction of demand and supply：練習題

In a perfectly competitive market, when the quantity demanded equals the quantity supplied, the market is said to be in:

Product \(X\) and product \(Y\) are in joint supply. Product \(X\) and product \(Z\) are in joint demand (complements).

If there is a substantial increase in the market demand for product \(Y\), what is the most likely effect on the equilibrium prices of products \(X\) and \(Z\)?

Product \(W\) requires component \(K\) for its production (derived demand). Component \(K\) is produced in joint supply with product \(L\). Product \(L\) is a substitute for product \(M\).

If the demand for product \(W\) increases significantly, what is the most likely effect on the equilibrium price and quantity of product \(M\)?

If the market supply of a product increases and, at the same time, the market demand for the product also increases, what will be the definite effect on the equilibrium price and quantity?

Consider a market for a particular brand of organic coffee. The demand and supply functions for this coffee are given by:

Demand: \( P_D = 100 - 2Q \)

Supply: \( P_S = 10 + 3Q \)

Where \( P \) is the price in dollars and \( Q \) is the quantity in kilograms.

(a) Calculate the equilibrium price and quantity in this market.

(b) Calculate the consumer surplus at this equilibrium.

(c) Calculate the producer surplus at this equilibrium.

(a) Define the terms consumer surplus and producer surplus.

(b) Using a clearly labelled demand and supply diagram, illustrate how an improvement in production technology for a good would affect the market equilibrium. Clearly indicate the areas representing consumer surplus and producer surplus before and after this technological improvement.

(c) Explain the impact of this technological improvement on consumer surplus and producer surplus, making reference to your diagram in (b).