Preferences消费者偏好(2)(必威体育精装版整理版).pptVIP

ChapterThreePreferences消费者偏好

WhereAreWeintheCourse?Wearestudyingthe1stofthethreeblocksofmicroeconomics:Consumerbehavior,productiontheory,andmarketequilibriumWithinthe1stblock,weareworkingonthe2ndofthethreecomponents:choiceset,preference,andconsumerdemand

WhatDoWeMeanbyPreference?(偏好)Itreferstotheorderedrelationshipamongalternativechoicesgivenbyaneconomicagent.Inmosteconomicliterature,consumerpreferenceistreatedastheultimateexogenouselement.

PreferenceRelationsComparingtwodifferentconsumptionbundles,xandy:strictpreference:xismorepreferredthanisy.weakpreference:xisasatleastaspreferredasisy.Indifference:xisexactlyaspreferredasisy.

Notationsdenotesstrictpreference;

~denotesindifference;denotesweakpreference;

p~f

PreferenceRelationsxyandyximplyx~y.xyand(notyx)implyxy.~f~f~f~fp

AssumptionsaboutPreferenceRelationsCompleteness:Foranytwobundlesxandyitisalwayspossibletomakethestatementthateither

xy

or

yx.~f~f

AssumptionsaboutPreferenceRelationsReflexivity:Anybundlexisalwaysatleastaspreferredasitself;i.e.

xx.~f

AssumptionsaboutPreferenceRelationsTransitivity:If

xisatleastaspreferredasy,and

yisatleastaspreferredasz,then

xisatleastaspreferredasz;i.e.

xyandyzxz.~f~f~f

IndifferenceCurves

无差异曲线(或,无差异集)Takeareferencebundlex’.Thesetofallbundlesequallypreferredtox’istheindifferencecurvecontainingx’;thesetofallbundlesy~x’.Sinceanindifference“curve”isnotalwaysacurveabetternamemightbeanindifference“set”.

IndifferenceCurvesx2x1x”x”’x’~x”~x”’x’

IndifferenceCurvesx2x1zxyppxyz

IndifferenceCurvesx2x1xAllbundlesinI1arestrictlypreferredtoallinI2.yzAllbundlesinI2