Limitations of the Closed Economy Model

Role of Financial Markets in Economic Models

Evaluating a Simplified Economic Model

An economist is developing a model to understand how a 10% increase in the price of coffee beans affects the purchasing habits of coffee drinkers. The model includes variables for consumer income, the price of coffee, and the price of tea, but it intentionally excludes factors like the overall rate of inflation, national unemployment rates, and global political events. What is the most compelling justification for this simplification?

A more effective economic model is always one that includes a greater number of real-world variables, as this makes the model more accurate and realistic.

The Purpose of Simplification

The Trade-off Between Realism and Usability in Economic Models

An economist needs to build a model to answer a specific question. Match each research question with the model simplification that would be most useful for the analysis, by focusing on the most relevant factors and excluding less important ones.

An economist creates a simple model to predict how a change in the price of orange juice affects the quantity people buy. The model's only prediction is that if the price of orange juice rises, people will buy less of it. For this prediction to be the sole focus, what must the model implicitly assume?

A city planner uses an economic model to evaluate the construction of a new public subway line. The model is designed to determine financial viability and only includes two variables: the total cost of construction and the total expected revenue from ticket sales over 30 years. Based on these two variables, the model concludes the project is unprofitable. What is the most significant analytical weakness of this simplified model when used to make a policy decision?

Designing a Minimum Wage Model

Assessing the Scope of an Economic Model