Fred has a Cobb-Douglas utility function with exponents that sum to 1.Sally consumes the same two goods, but the two goods are perfect substitutes for her.Despite these differences, Fred and Sally have the same price offer curves.

Cobb-Douglas

A type of production function used in economics to represent the relationship of an output to inputs, specifically capital and labor, with constants denoting the output elasticity of each input.

Perfect Substitutes

Two or more goods that can be used in place of one another with no loss of utility for the consumer, resulting in constant marginal rates of substitution.