<p>Pallak Goyal gave what I think can reasonably be assumed to be the answers the author was looking for.</p>
<p>This answer is a comment that would not fit under the actual comments. The idea behind (a) and (c) is that in order to be rational, an individual must &quot;have&quot; a complete and transitive preference relation. The &quot;have&quot; here is pretty loaded, and much of mainstream economics would take a very different view- a view that happens to be more behaviorally focused than, ironically, what many people in behavioral economics do.</p>
<p>What do we mean when we say a decision-maker prefers an apple to a banana?  The <a href="https://en.wikipedia.org/wiki/Revealed_preference" rel="nofollow noreferrer">revealed preference</a> approach, followed by the majority of mainstream economists, is that this simply means that the decision-maker would choose an apple if given the choice between an apple and a banana. One gives the decision-maker some options and observes what the decision-maker does. Apparently, whatever they chose is revealed preferred to the other alternatives. In the example of Buridan's ass, the ass seems to prefer starvation to the alternatives. Since one always chooses something, revealed preferences are automatically complete. In this context, incompleteness is meaningless. However, completeness together with transitivity has some strong implications- at least if one makes identifying assumptions that rule out that decision-maker is indifferent between all conceivably choices. That the lead character of a novel &quot;is not indifferent and cannot form a weak preference either way.&quot; is a rather odd statement when viewed this way.</p>

CC BY-SA 4.0
2022-05-15T22:11:27.733Z
2022-05-15T22:11:27.733Z
Michael Greinecker
<p>a) If Sophie is not indifferent between all options, then completeness requires that she have some ranking between atleast 2 of them. In this case, she must weakly prefer one option to the others.So completeness condition is violated, and Sophie is irrational.</p>
<p>b)The question uses the words&quot;so on&quot;. So the professor must be preffering a 200d bottle to a 198d bottle. It is given that he weakly prefers 8d bottle to 200d bottle. This violates transitivity.</p>
<p>c) The ass does not have complete preferences. Had the preferences been complete they would have been:
<span class="math-container">$Eat\approx Drink&gt;Go Hungry$</span></p>

CC BY-SA 4.0
2022-05-15T09:38:07.560Z
2022-05-15T09:43:41.777Z
2022-05-15T09:43:41.777Z
Pallak Goyal
<p>I am reading <em>A Course in Behavioral Economics</em> third edtion written by Erik Angner.</p>
<p>I am struggling with page 30, exercise 2.40:</p>
<blockquote>
<p>Exercise 2.40 Irrationality  Explain (in words) why each of the characters below is irrational according to the theory you have learned in this chapter.</p>
<p>(a) In the drama Sophie’s Choice, the title character finds herself in a Nazi concentration camp and must choose which one of her children is to be put to death. She is not indifferent and cannot form a weak preference either way.</p>
<p>(b) An economics professor finds that he prefers a \$10 bottle of wine to an \$8 bottle, a \$12 bottle to a \$10 bottle, and so on; yet he does not prefer a \$200 bottle to an \$8 bottle.</p>
<p>(c) Buridan’s ass is as hungry as it is thirsty and finds itself exactly midway between a stack of hay and a pail of water. Unable to decide which is better, the animal expires.</p>
</blockquote>
<p>For a, it is impossible that she is not indifferent and cannot form a weak preference either way. There must be some preference relationship as it is complete.</p>
<p>For c, unable to decide means indifference, there is nothing irrational.</p>

CC BY-SA 4.0
2022-05-15T06:27:51.090Z
I guess that should depend on the "theory you learned in this chapter." Except for b, standard theories of choice seem nit to be applicable.
Michael Greinecker
<behavioral-economics><rationality>
How are these examples irrational?
martinrhan
# How are these examples irrational?

(Asked by: username_0 on 2022-05-15)

I am reading *A Course in Behavioral Economics* third edtion written by Erik Angner.

I am struggling with page 30, exercise 2.40:

> Exercise 2.40 Irrationality Explain (in words) why each of the characters below is irrational according to the theory you have learned in this chapter.
>
> (a) In the drama Sophie’s Choice, the title character finds herself in a Nazi concentration camp and must choose which one of her children is to be put to death. She is not indifferent and cannot form a weak preference either way.
>
> (b) An economics professor finds that he prefers a \$10 bottle of wine to an \$8 bottle, a \$12 bottle to a \$10 bottle, and so on; yet he does not prefer a \$200 bottle to an \$8 bottle.
>
> (c) Buridan’s ass is as hungry as it is thirsty and finds itself exactly midway between a stack of hay and a pail of water. Unable to decide which is better, the animal expires.

For a, it is impossible that she is not indifferent and cannot form a weak preference either way. There must be some preference relationship as it is complete.

For c, unable to decide means indifference, there is nothing irrational.

**Tags:** behavioral-economics, rationality

> **Comments:**
> **username_1**: I guess that should depend on the "theory you learned in this chapter." Except for b, standard theories of choice seem nit to be applicable.  

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## 2 answers

### Answer by username_2 on 2022-05-15. Score: 4 | Accepted answer

a) If Sophie is not indifferent between all options, then completeness requires that she have some ranking between atleast 2 of them. In this case, she must weakly prefer one option to the others.So completeness condition is violated, and Sophie is irrational.

b)The question uses the words"so on". So the professor must be preffering a 200d bottle to a 198d bottle. It is given that he weakly prefers 8d bottle to 200d bottle. This violates transitivity.

c) The ass does not have complete preferences. Had the preferences been complete they would have been:
$Eat\approx Drink>Go Hungry$


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### Answer by username_1 on 2022-05-15. Score: 3

username_2 username_2 gave what I think can reasonably be assumed to be the answers the author was looking for.

This answer is a comment that would not fit under the actual comments. The idea behind (a) and (c) is that in order to be rational, an individual must "have" a complete and transitive preference relation. The "have" here is pretty loaded, and much of mainstream economics would take a very different view- a view that happens to be more behaviorally focused than, ironically, what many people in behavioral economics do.

What do we mean when we say a decision-maker prefers an apple to a banana? The [revealed preference](https://en.wikipedia.org/wiki/Revealed_preference) approach, followed by the majority of mainstream economists, is that this simply means that the decision-maker would choose an apple if given the choice between an apple and a banana. One gives the decision-maker some options and observes what the decision-maker does. Apparently, whatever they chose is revealed preferred to the other alternatives. In the example of Buridan's ass, the ass seems to prefer starvation to the alternatives. Since one always chooses something, revealed preferences are automatically complete. In this context, incompleteness is meaningless. However, completeness together with transitivity has some strong implications- at least if one makes identifying assumptions that rule out that decision-maker is indifferent between all conceivably choices. That the lead character of a novel "is not indifferent and cannot form a weak preference either way." is a rather odd statement when viewed this way.


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