Final answer:
An individual makes a rational choice in economics by assessing perceived benefits against costs and choosing an action that maximizes personal advantage.
Step-by-step explanation:
When an economist says that an individual has to make a rational choice, they mean that the individual has made a decision based on their own best interests, after considering all available information. Traditional economic models assume that people are rational agents who consistently make decisions that maximize their utility.
However, everyday behaviors and choices can seem irrational and not in one's best interest, such as not taking opportunities to save money or time. In the context of economics, a rational decision is one where an individual assesses the perceived benefits and costs and chooses an action if the benefits outweigh the costs. Economics professors often use real-life instances of seemingly irrational behaviors to illustrate the principles of rational decision-making to their students.