This is illustrated by Korky Paul, who is my absolute favourite illustrator. The story is about what in economics we call an externality: when something that somebody produces has either a benefit or a cost for other people that is not included in the price. So in this case it’s the smell of the baked goods – other people can enjoy the smell, but they don’t have to pay for it. That’s a positive externality. A negative externality is pollution: when firms produce goods but they pollute the environment and nobody pays for it. It’s a very sophisticated concept, and yet here it is, in this picture book for young children.