This photo of agricultural terrace captured my attention.
In the photo, fields are cultivated on a slight slope. The puzzle is why the Chinese prefer to shape their fields on a slight slope given the option that they can completely flatten the surface? Isn't flat surface more convenient for farmers and draft animals to walk on? Is it because the cost of channeling water to the fields would be lower when there is a slope?
Here is the economic analysis: By cultivating narrow terraces on a hill or slope, the farmers maximize the use of flat surfaces subject to the cost of flattening the surfaces. I'm using a price discrimination diagram to demonstrate the benefits of narrow terraces. If a slope is divided into infinitely narrow rings of terrace, the total size of surfaces would converge to the size of the slope. Therefore, the narrower the rings are, the greater the total size of surfaces of the rings. Given the high labor-land ratio in China, how to maximize the surface of agricultural land is a major concern.