Editing Utility (section)

===Revealed preference===
It was recognized that utility could not be measured or observed directly, so instead economists devised a way to infer relative utilities from observed choice. These 'revealed preferences', as termed by [[Paul Samuelson]], were revealed e.g. in people's willingness to pay: 
<blockquote>
Utility is assumed to be correlative to Desire or Want. It has been argued already that desires cannot be measured directly, but only indirectly, by the outward phenomena which they cause: and that in those cases with which economics is mainly concerned the measure is found by the price which a person is willing to pay for the fulfillment or satisfaction of his desire.<ref>{{cite book |first=Alfred |last=Marshall |year=1920 |title=Principles of Economics. An introductory volume |edition=8th |location=London |publisher=Macmillan }}</ref>{{RP|78}}</blockquote>