Assumptions Underlying the Law of Demand
Demand
AO2·HL
Syllabus requirement
Rational consumer behavior, utility maximization, ceteris paribus.
Assessment objectives
AO2 Application and Analysis
Higher LevelThis topic is assessed at HL.
Summary
This topic explains the assumptions that generate the negative relationship between price and quantity demanded for HL students. It focuses on the income effect and the substitution effect, describing how a fall in price raises consumers' real income and makes the good relatively cheaper compared with substitutes, both leading to increased quantity demanded. Understanding these effects helps explain why demand curves slope downwards.