Wine growers reeling from the coronavirus pandemic have slammed the state environment department over the timing of controlled burns in the Macedon ranges that they fear will damage their harvest. A last-minute attempt by lawyers to stop the first of three burns failed yesterday, with the blaze sending ripples of panic through vineyards where grapes are in the last stages of ripening and particularly vulnerable to smoke taint. Wine growers have been pleading with state authorities to halt the burn for a few weeks until their crops have been harvested.

a] (1 point) Explain why there is likely to be an external effect associated with the decision made by the state environment department about the timing of controlled burns? (A controlled burn is where bushland is set fire to, in order to reduce the size of any unintended fire that might occur in that area.)

b] (1/2 point) What does the existence of the external effect imply about the timing of the controlled burns compared to the socially optimal timing?

c] (1/2 point) What do you think would be the most effective policy solution to ensure socially optimal timing of the controlled burn?