Which of the following is the basis for constructing Indifference Curve (IC)?

Question

Accepted Answer

The correct option is 4:
The basis for constructing an Indifference Curve (IC) is the Consumer preference scale. An Indifference Curve is a graphical representation of various combinations of two goods that provide the consumer with the same level of satisfaction or utility. The core assumption of indifference curve analysis is that a consumer can rank or order their preferences among different bundles of goods, which is exactly what the consumer preference scale represents. This scale is the foundation of the ordinal utility approach, where the magnitude of utility is irrelevant, but the consumer's ability to rank combinations is paramount. Therefore, the shape and position of an IC are derived entirely from the consumer's subjective tastes and preferences, illustrating combinations that yield equal utility.

The incorrect option is 1:
Consumer's Income is incorrect because while income is crucial in determining which bundles a consumer can *afford*, it is represented by the Budget Line, not the Indifference Curve itself. A change in income causes the Budget Line to shift parallel, indicating a change in purchasing power, but it does not change the underlying structure of the consumer's preferences, which is what the IC measures. Indifference curves are drawn assuming a given set of preferences, independent of the consumer’s income level. Thus, income affects the consumer's equilibrium (where the IC is tangent to the Budget Line) but is not the basis for the curve's construction.

The incorrect option is 2:
Absolute prices of two goods are incorrect. Similar to income, absolute prices are a component of the Budget Line, defining its exact position and intercept points on the axes. The IC is concerned only with the comparison of utility between different combinations of goods based on preference. Absolute prices indicate how much of one good must be given up to obtain a certain amount of the other good in the market, but they do not influence the consumer’s internal ranking of satisfaction.

The incorrect option is 3:
Relative prices of two goods are incorrect. Relative prices are the slope of the Budget Line, specifically representing the Market Rate of Exchange (MRE) between the two goods. While relative prices play a critical role in consumer choice and determining the point of optimal consumption, the Indifference Curve's slope is the Marginal Rate of Substitution (MRS), which is based purely on the consumer's willingness to substitute one good for another to maintain the same level of utility (preference). The IC is derived from preference, whereas relative prices are determined by market conditions.