1.3.2.5a - YED calculation

Calculate income elasticity of demand.

Use a - yed calculation to connect the rule to the data and decision in the question.

This matters because a - yed calculation determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply a - yed calculation to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: a - YED calculation is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.