What effect will an increase in the supply of fish have on the meat market

Step 1: Analyze the question Fish and meat are substitutes: consumers can replace one with the other. The question asks how a change in the fish market (an increase in supply) affects the meat market.

Step 2: The concept

• When the supply of fish increases, the price of fish falls.
• Fish becomes cheaper relative to meat, so consumers buy more fish and less meat.
• For meat, this means a fall in demand, so the demand curve shifts to the left.

Step 3: Effect on the meat market

• Demand for meat decreases (leftward shift of the demand curve).
• With supply unchanged, the new equilibrium is at a lower price and a lower quantity.

| Event | Effect | |---|---| | Supply of fish rises | Price of fish falls | | Fish is cheaper (a substitute) | Demand for meat falls | | Demand curve for meat shifts left | Equilibrium price and quantity of meat both fall |

Step 4: Checking the options

• A. A fall in equilibrium price and quantity: correct, as shown above.
• B. Both rising would need an increase in demand for meat, which would happen if fish became more expensive.
• C. A higher price with lower quantity would need a fall in supply of meat, which is not the case here.
• D. Unchanged is wrong because the substitute's price change does shift meat demand.

Exam tip: For related goods, remember:

• Substitutes (fish and meat, tea and coffee): a price fall in one lowers demand for the other.
• Complements (car and petrol): a price fall in one raises demand for the other.

Always ask first: which curve shifts in the market the question is about? Here it is the demand curve for meat, moving left.