econ急問!!!! 關於”問點解汽水既價錢系餐廳賣會貴過系超級市場!

It was because price elasticity of demand on soft drinks in Spaghetti was lower than that in Park'N. That's means you must order soft drinks in Spaghetti as you can not purchase them in other places and bring them into Spaghetti. However, you can choose to buy them elsewhere when you are in Park'N. You can drink a vert steep demand curve on soft drinks when you are in Spaghetti, hence percentage increase in price is higher than % drop in quantity demanded.

雖然超市同餐廳取貨成本是一樣的，
但超市有很多其他貨物一同出售，
是超市出售的主力所在，
所以汽水可以較便宜一樣．

餐廳主力賣的是即食新鮮食物，
汽水多半是要向生產商取得許可，
才能在餐廳中出售，
所以可能會較貴