The weak rationality principle is a key concept in economics that helps us understand how people make decisions. It suggests that people act in a way that makes sense to them, even if it may not always seem rational to others. This principle is important for creating economic models that are based on individual behavior. The idea of 'bounded rationality' acknowledges that people have limited information when making choices. Additionally, the assumption of self-interest is often included in economic models. Overall, this approach helps economists address issues like free will and weakness of will when studying human behavior in the context of economics.