Axioms:

Revealed preference theory is based on the axioms listed below. 

•  Consumer will spend all her income on goods. The consumer equilibrium always remains on the budget line. 

•  For any given price income situation, there corresponds a unique commodity bundle that the consumer chooses. Given the same income and prices, consumer will always choose the same bundle. 

•  For any given bundle, there is always a unique price income situation in which the consumer will be led to purchase that bundle. 

•  Weak axiom of revealed preference: If consumer chooses a bundle q₀ in some price income situation (p₀, M₀) and spurns q₁, where q₁ is not more expensive than q0 at the prices at which q₀ is bought, then q0 is revealed preferred to q₁. Then q₁ can never be revealed preferred to q₀ when q₀ is available. If in another price situation, consumer chooses the bundle q₁, then q0 is not an available alternative at that price situation. 

•  Demand function is single valued in prices and income.