文档介绍：Chapter Seven
Revealed Preference
显现性偏好
What Is the Question of the Chapter?
Suppose we observe a collection of a consumer’s choices, can we discover his/her preference?
Is this possible at all? If so, under what conditions is this possible?
(This is the reverse question of finding the optimal choice)
Digression: Science vs. Engineering (对比科学家思维与工程师思维)
找问题与解问题的不同
要对问题提问题
务虚与务实的不同
解释世界与改造世界的不同
旁观者与参与者的不同
Maintained Assumptions on Preferences
Preferences
do not change while the choice data are gathered.
are strictly convex.
are monotonic.
Assumptions on Preferences
x2
x1
x1*
x2*
If preferences are convex and monotonic (. well-behaved) then the most preferred affordable bundle is unique.
Direct Preference Revelation
Suppose that the bundle x* is chosen when the bundle y is affordable. Then x* is revealed directly as preferred to y (otherwise y would have been chosen).
Direct Preference Revelation
x2
x1
x*
y
The chosen bundle x* is revealed directly as preferred to the bundles y and z.
z
Direct Preference Revelation
That x is revealed directly as preferred to y will be written as x y.
D
p
Indirect Preference Revelation
Suppose x is revealed directly preferred to y, and y is revealed directly preferred to z. Then, we call x is revealed indirectly as preferred to z. Write this as x z so x y and y z x z.
D
p
D
p
I
p
I
p
z is not affordable when x* is chosen. x* is not affordable when y* is chosen. So x* and z cannot pared directly.
Indirect Preference Revelation
x2
x1
x*
y*
z
But x*x* y* and y* z so x* z.
D
p
D
p
I
p