At frank's delicatessen, frank noticed that the elasticity of customers differed in the short and longer term. frank also noticed that his increase in the price of sandwiches had other effects on his store. in particular, the number of sodas sold declined while the number of yogurts sold went up. how might you explain this pattern? if soda is a complement to sandwiches, then the cross-price elasticity is thus, as frank loses sandwich sales from the price increase, he will lose soda sales as well. if yogurt, on the other hand, is a substitute for sandwiches, then the cross-price elasticity is thus, as the price of sandwiches increases, more yogurt is consumed.
a. negative; negative
b. positive; negative
c. positive; positive
d. negative; positive