In real life, people are always faced with limited resources. The limited nature of resources refers to the fact that a specific type of resource has a clearly limited value in the traditional sense, such as the proven coal reserves in a certain area. It can also be an invisible constraint faced by an individual, such as the sum of a day’s work or leisure time that an individual can allocate. A fundamental problem facing economists is how to allocate limited resources to maximize social or individual welfare. It is the unremitting pursuit of optimizing resource allocation that has driven the dynamic development of modern economic theory.