Two cities tried different ways to reduce plastic waste. One city gave free reusable bags to shoppers, while the other charged a small fee for plastic bags. The first plan was popular, but many people forgot to bring the bags again. The second plan was less popular at first, yet stores reported a larger decrease in plastic bag use. The writer concludes that a small cost can sometimes change habits more effectively than a free gift.
while、but、yet の後に比較のポイントがあります。