1. Consumer choice

2. Utility film
level of happiness or satisfaction associated with alternative choices
a term referring to the satisfaction received by a consumer from consuming a good or service
utility maximization
The doctrine of utilitarianism saw the maximization of utility as a criterion for the organization of society. According to utilitarians, such as Jeremy Bentham (1748– 1832) and John Stuart Mill (1806–1873), society should aim to maximize the total utility of individuals, aiming for "the greatest happiness for the greatest number of people".

3. Total and marginal utility
total utility (TU) - the level of happiness derived from consuming the good
marginal utility (MU) - the additional utility that is received when an additional unit of a good is consumed

4. Marginal utility (MU) # of bananas total utility marginal utility 0 0 - 70 40 20 10 5 -5

5. Law of diminishing MU (Gossen's First Law)
law of diminishing marginal utility - marginal utility declines as more of a particular good is consumed in a given time period, ceteris paribus
even though marginal utility declines, total utility still increases as long as marginal utility is positive. Total utility will decline only if marginal utility is negative.

6. Diamond-water paradox film, film2
As noted by Adam Smith, water is essential for life and has a low market price (often a price of zero) while diamonds are not as essential yet have a very high market price.
Smith’s explanation: “value in use” vs. “value in exchange”

7. MU of water and diamonds

8. TU of water and diamonds

9. Value in use and value in exchange
value in use = total utility
value in exchange is related to marginal utility

10. Consumer equilibrium 1. 2. All income is spent.
The first condition listed above is sometimes referred to as the "equimarginal principle."

11. Consumer surplus
Individuals buy an item only if they receive a net gain from the purchase (i.e., total benefit exceeds opportunity cost).
This net gain is called “consumer surplus.”

12. Example
Suppose that an individual buys 10 units of a good when the price is $5

13. Benefits and cost of first unit
Benefit = blue + green rectangles (=$9)
Cost = green rectangle (=$5)
Consumer surplus = blue rectangle (=$4)

14. Total benefit to consumer

15. Total cost to consumer

16. Consumer surplus

17. Indifference curves
Indifference curve – a graph of all of the combinations of goods that provide a given level of utility
Any two points on an indifference curve provide the same level of utility

18. Points on and off an indifference curve

19. Alternative levels of utility

20. Budget constraint film film2

21. Optimal consumption bundle
the point on the budget line that maximizes a consumer's total utility
the tangency of the budget line and an indifference curve

22. Bibliography www.oswego.edu/~kane/eco101.htm
Czarny B. Podstawy ekonomii
en.wikipedia.org/wiki/Utility