Robin Crusoe is the only survivor of a shipwreck. She is stranded on a tropical island. She survives at first by finding shelter in a small cave, gathering shellfish and tree fruits to eat, and drinking from a freshwater stream. In time, she discovers where edible plants can be found and how to trap animals for food. She makes tools. She builds a tree house. She constructs a canoe, which takes her to good fishing spots. She collects nuts and saves them to eat in the winter season. She builds a reed hut, and later, in time, a cottage. Eventually, she learns to cultivate indigenous seeds for a vegetable garden. She tames some wild goats for milk and cheese. Does Robin have an economy? Can you please explain. Thank you in advance!