Sidney chooses pies on the basis of popularity. Apple pie is more popular than blueberry pie. Apple pie is so popular that pie eaters have grown sick of it. They quickly gorge on the new cherry pie. When the fad dies down, they are still sick of apple pie and begin a blueberry revival. Sidney correctly predicts that blueberry will be more popular.
His preferences in that scenario do not violate independence of irrelevant alternatives (that might be your point; I’m not sure). This is meant as an intuition pump to show the absurdity of violating IIA, not a watertight argument that the observed behaviour does in fact violate it.
Sidney chooses pies on the basis of popularity. Apple pie is more popular than blueberry pie. Apple pie is so popular that pie eaters have grown sick of it. They quickly gorge on the new cherry pie. When the fad dies down, they are still sick of apple pie and begin a blueberry revival. Sidney correctly predicts that blueberry will be more popular.
His preferences in that scenario do not violate independence of irrelevant alternatives (that might be your point; I’m not sure). This is meant as an intuition pump to show the absurdity of violating IIA, not a watertight argument that the observed behaviour does in fact violate it.