Input approach to determining comparative advantage | AP Macroeconomics | Khan Academy

Understanding Input and Output in Production Possibility Curves

Introduction to Input vs. Output

• The video begins by discussing the transition from output tables to input tables for calculating opportunity costs in production. This shift allows for a different perspective on comparative advantage.

Worker Hours as Inputs

• A table is introduced showing worker hours required per item in two countries:

• Country A requires 2 hours to produce one toy car and 1 hour for one belt.

• Country B requires 4 hours for a toy car and 3 hours for a belt.

Constructing an Output Table

• The instructor proposes converting the input data into an output table, assuming each worker has 8 working hours per day.

• Viewers are encouraged to calculate how many units of toy cars and belts can be produced per worker per day in both countries.

Calculating Outputs

• For Country A:

• Workers can produce 4 toy cars (8 hours / 2 hours per car).

• Workers can produce 8 belts (8 hours / 1 hour per belt).

• For Country B:

• Workers can produce 2 toy cars (8 hours / 4 hours per car).

• Workers can produce approximately 2.67 belts or 8/3 belts (8 hours / 3 hours per belt).

Opportunity Cost Analysis

• The concept of opportunity cost is introduced, with a new table set up to analyze it based on previously calculated outputs.

Opportunity Cost in Country A

• In Country A, producing 1 toy car costs the equivalent of producing 2 belts, derived from the ratio of total outputs.

• Conversely, producing 1 belt costs half a toy car, highlighting reciprocal opportunity costs between products.

Opportunity Cost in Country B

• In Country B, the same energy used to make 2 toy cars could instead yield 8/3 belts, leading to an opportunity cost of about 4/3 or approximately 1.33 belts per car.

Comparative Advantage in Toy Cars and Belts

Understanding Opportunity Cost

• To determine which country has a comparative advantage in toy cars, we compare the opportunity costs. Country A's opportunity cost is two belts for one toy car, while Country B's is only 1 1/3 belts.

Identifying Comparative Advantages

• Country B holds the comparative advantage in producing toy cars due to its lower opportunity cost. Conversely, Country A has a comparative advantage in belts since its opportunity cost is less than that of Country B (1/2 of a car vs. 3/4 of a car).

Efficiency vs. Opportunity Cost

• Despite Country A having an absolute advantage (workers can produce four cars compared to two in Country B), the concept of comparative advantage suggests that it makes more sense for Country B to focus on toy cars and for Country A to concentrate on belts.

The Big Picture: Input vs. Output Lens