Problems on Prospect Theory

Print out as many copies of this figure, adapted from Plous, p. 96, as you need for the following problems.


Problem #1:

On page 70, Plous discusses the responses subjects give to choices between options A and B, and then options C and D. On page 71, he compares combined choice A & D with combined choice B & C. So he analyzes a total of six possible choices in all, four simple and two combinations.

a)    For each of these six compute its expected utility, assuming that utility is determined by the dollar amount.

b)    Now using the Prospect Theory graph above (use the horizontal axis to represent dollar amounts and the vertical axis to represent units of subjective value), compare the various options.

c)    Does using the notion of value postulated by Prospect Theory explain the way people respond to these various options completely or do we still need to talk about attitudes toward probability and/or certain outcomes?

 

 

Problem #2:

On pages 74 and 75, Plous describes the jacket/calculator puzzle. Can one use the graph above to explain why people feel that the difference between $15 and $10 is greater than the difference between $125 and $120?

If so, does this resolve all the puzzlement about the example? If no, how can  we understand this bit of decision behavior – or can we?

Problem #3:

The Bazerman article on "Framing" (posted on e-reserve) begins with a description of an early Tversky and Kahneman experiment concerning the outbreak of an "unusual disease" that is expected to kill 600 people and describes four options.

        

a)    For each of these four compute its expected (dis)utility, assuming that utility is determined by the number of lives lost.

b)    Now using the Prospect Theory graph above (use the horizontal axis to represent number of lives and the vertical axis to represent units of subjective value), compare the various options.

c)    Does using the notion of value postulated by Prospect Theory explain the way people respond to these various options completely or do we still need to talk about attitudes toward probability and/or certain outcomes?

d)    (Optional) What do you think about using this sort of graph to compare the subject values of differing numbers of human lives?

   

Problem #4:

         On page 99, Plous discusses four options and describes people’s reactions to them.

 

a)    Is Rational Choice Theory helpful in understanding their responses? Explain briefly.

b)    Does the Prospect Theory account of value (and the above graph) explain their responses? Explain briefly.

c)    Does the Prospect Theory of decision weights and the graph on Plous, p. 98 explain their responses? Explain briefly.

d)    Is it also necessary to postulate a “certainty effect” in this case? Explain briefly.

 

Problem #5:

Compare the following two situations:

Situation 1: Would you volunteer to receive a vaccine that would be 50% effective in preventing a disease that is expected to afflict 20% of the population?

Situation 2: There are two mutually exclusive and equally probable strains of the disease, each of which is expected to affect 10% of the population. The vaccine offers complete protection against one strain and none against the other.

In one particular study (which gave more details about the situations), about 40% of the subjects said Yes to Situation 1, but only 57% of the respondents opted for the vaccine in Situation 2.

a)             From the perspective of Rational Choice Theory, how do the two situations differ?

b)             Does the Prospect Theory of value help explain the different responses to these situations? Explain.

c)             Does the Prospect Theory of weights help explain the different responses? Explain.

d)             This illustrates the phenomenon of “pseudocertainty”. Briefly explain.