Final answer:
The question asks for a scenario that would result in a decrease in both the real price of eggs and the total annual consumption of eggs. The correct answer is Option b: a simultaneous leftward shift in both the supply and demand curves, which leads to an unambiguous decrease in the equilibrium quantity and an ambiguous impact on price, but given the historical data on actual price decrease, this would be the cause.
Step-by-step explanation:
To determine the cause of an unambiguous decrease in both the real price of eggs and the total annual consumption of eggs, we need to consider the effects of shifts in both the supply and demand curves. Let's review the given options:
- Option a: A leftward shift in the supply curve would typically increase the equilibrium price, while a rightward shift in the demand curve would increase both the equilibrium price and quantity.
- Option b: A leftward shift in the supply curve would increase the equilibrium price and decrease the equilibrium quantity. A leftward shift in the demand curve, however, would decrease both the equilibrium price and quantity. Therefore, a simultaneous leftward shift in both the supply and demand curves for eggs would result in an ambiguous change in the equilibrium price but an unambiguous decrease in the equilibrium quantity.
- Option c: This option suggests that none of the other choices would lead to both a decrease in the real price and quantity consumed of eggs, which aligns with our assessment of options a and b.
- Option d: A rightward shift in the supply curve would lead to a decrease in the equilibrium price and an increase in the equilibrium quantity, whereas a rightward shift in the demand curve would increase both the equilibrium price and quantity.
Given these analyses, the correct answer is Option b: A shift to the left in the supply curve and a shift to the left in the demand curve for eggs. This is the only scenario provided that could lead to a decrease in both price and quantity consumed.