Economics (AS & A Level) · Feb / March 2023 · Paper 12 · Question 11

Butter and buttermilk are goods in joint supply. Supply curves in both markets slope upwards to the right. Health concerns cause people to reduce their consumption of butter. What are the initial consequences of this for supply in the markets for butter and buttermilk?

1. Asupply of butter: move left along supply curve; supply of buttermilk: move left along supply curve
2. Bsupply of butter: move left along supply curve; supply of buttermilk: shift left of the supply curve
3. Csupply of butter: shift left of the supply curve; supply of buttermilk: move left along supply curve
4. Dsupply of butter: shift left of the supply curve; supply of buttermilk: shift left of the supply curve

As printed in the paper