Marginal Utility and Indifference Curve

- If the consumption of a product moves along an indifference curve, additional utility derived from the increase in consumption of single good, food (F), should balance the loss of utility from decrease in consumption in other good, clothing (C).

* Formally:

* Rearranging:  

  Because:

*  When the consumers maximize satisfaction the:

* Since the MRS is also equal to the ratio of the marginal utilities of consuming F and C, it follows:


*  Which gives equation for the utility maximization?


* Total utility is maximized when budget is allocated such that the marginal utility per dollar of expenditure is same for every good.

* This can be referred to as equal marginal principle.