Professor : Soe-Tsyr , Yuan Presenter : Sherry

1. Endogenizing Prospect Theory’s Reference Point by Ulrich Schmidt and Horst Zank Professor : Soe-Tsyr, Yuan Presenter : Sherry

2. Outline • Abstract • Introduction • Prospect Theory Function • Endogenous Prospect Theory • What is “Preference” • Main condition in paper • Conclusion

3. Review Prospect Theory • Prospect theory is a behavioral economic theory that describes the way people chose between probabilistic alternatives that involve risk, where the probabilities of outcomes are known. • The theory states that people make decisions based on the potential value of losses and gains rather than the final outcome, and that people evaluate these losses and gains using certain heuristics.

4. Abstract • In previous models of (cumulative) prospect theory reference-dependence of preferences is imposed beforehand andthe location of the reference point is exogenously determined. • This note provides a foundation of prospect theory, where reference-dependence is derived from preference conditions and a unique reference point arises endogenously.

5. Introduction • Prospect theory is currently one of the most influential models of decision making under uncertaintyand has been applied in various fields like finance, consumer choice, and political decision making. • Reference-dependence means that people do not evaluate final outcomes but instead they base decisions on gains and losses relative to a reference point.

6. Prospect Theory Function • current axioms of PT assume the existence of a preference relationdefined on gains and losses relative to an exogenously fixed reference pointand then impose behavioral conditions on this (reference-dependent) preference relation. • As a consequence, PT can neither be tested nor applied to concrete choice problemswithout making prior assumptions about the location of the reference point. • This is sometimes interpreted as a major shortcoming of prospect theory.

7. Endogenous Prospect Theory • The goal of the present note is to derive a new foundation for the model. • We call the new approach endogenous prospect theory (EPT) because reference-dependence is not assumed beforehand but derived from a behavioral foundation.

8. Endogenous Prospect Theory • As mentioned above, according to previous models of prospect theory two criteria can be used to identify the reference point, diminishing sensitivity and loss aversion. • In EPT we focus on diminishing sensitivity. • By imposing our central axiom —termed consistent diminishing sensitivity— reference dependence arises endogenously in our model and the reference point is located at the position at which sensitivity towards changes in outcomes is maximal.

9. Preference

10. Preference Complete: whenever A > B and B > C, then also A > C whenever A ≥ B and B ≥ C, then also A ≥ C whenever A = B and B = C, then also A = C. Transitive:

11. Prospect Theory Function … represent all of possible results; represent the probability of all of the results; is value function, and it means the relatively value in the decision-maker’s mind; is probability weighting function, and it means the reaction of most people face probability.

12. Prospect Theory Function • Prospect theory generalizes CEU by introducing a reference-point , which may impact on utility and capacity. In all axiomatic work we are aware of, the existence and location of this reference-point is assumed exogenously.

13. Prospect Theory Function

14. Main condition in paper

15. Main condition in paper

16. Such a finding is in agreement with risk aversion in the sense of diminishing marginal utility for increments in outcomes. This latter finding is in agreement with risk seeking in the sense of diminishing marginal utility for decrements in outcomes.

19. Conclusion • theory build on existing tools that were used to derive PT with exogenous reference points. • How to detect the reference pointis a shortcoming in earlier derivations of PT, which has often been criticized, and our note proposes a solution that overcomes this hurdle.

20. Value • For PT to become a valuable tool for economic analyses the model needs a theoretical foundation of how to detect the reference point from preferences.

21. How to apply_1 • In my research, I trend to evaluate the utilize value of making decision. In advance, I must to detect the current reference point that user hold. • The tool is proposed by this paper can help us base on user’s preference to gain their reference point.

22. How to apply_2 • Paper said “reference-dependence is derived from preference conditions and a unique reference point arises endogenously” • Regard “endogenously” as personal behavior. • It means someone’s reference point can be changed by their behavior.

23. In our platform ? Apply Media Industry to illustrate

24. View of ECONOMY In Macroeconomics This way can’t aim the individual’s behavior to design the contents. NO. 1 Media Platform exogenously Individual access news on demand

25. View of ECONOMY In Microeconomics Detect every user’s current reference point, and evaluate the utilize value to move it to the best one. endogenously When every user have good behavior in media domain, then the media industry will be great.

26. Q&A • Can we find more factors that impact the location of reference point ? • And, how to move the location of reference point ?