Editing Psychological pricing (section)

===In consumer behavior===
Thomas and Morwitz (2005) suggested that this bias is a manifestation of the pervasive anchoring heuristic in multi-digit comparisons. (The anchoring heuristic is one of the heuristics identified by Nobel laureate Kahneman and his co-author Tversky.) Judgments of numerical differences are anchored on leftmost digits, causing a bias in relative magnitude judgments.<ref>{{cite journal|last1=Thomas|first1=Manoj|last2=Morwitz|first2=Vicki|volume=32|issue=1|date=June 2005|title=Penny Wise and Pound Foolish: The Left-Digit Effect in Price Cognition|journal=Journal of Consumer Research|pages=55–64|doi=10.1086/429600 |citeseerx=10.1.1.519.6272}}</ref> This hypothesis suggests that people perceive the difference between 1.99 and 3.00 to be closer to 2 than to 1 because their judgments are anchored on the leftmost digit.

Stiving and Winer (1997) examined the left-digit effect using scanner panel models. They proposed that 9-ending prices can influence consumer behavior through two distinct processes: image effects and level effects. Image effect suggests that 99-ending prices are associated with images of sales promotions. Level effect captures the magnitude underestimation caused by anchoring on the leftmost digits of prices. Their results suggest that both of these effects account for the influence of 9-ending prices in grocery stores.<ref>{{Cite journal|doi = 10.1086/209493|title = An Empirical Analysis of Price Endings with Scanner Data|year = 1997|last1 = Stiving|first1 = Mark|last2 = Winer|first2 = Russell S.|journal = Journal of Consumer Research|volume = 24|pages = 57–67}}</ref> Manning and Sprott (2009) demonstrated that left-digit anchoring can influence [[consumer choice]]s using experimental studies.<ref name=":0" />

Choi, Lee, and Ji (2012) examined the interactive effects of 9-ending prices and message framing in advertisements. The researchers found that when pairing nine-ending prices with positive messages, advertisements were much more positively received by consumers. This in turn increased their likelihood of making a purchase decision.<ref>{{Cite journal|doi=10.1007/s11002-012-9164-7|title=What type of framing message is more appropriate with nine-ending pricing?|year=2012|last1=Choi|first1=Jungsil|last2=Lee|first2=Kiljae|last3=Ji|first3=Yong-Yeon|journal=Marketing Letters|volume=23|issue=3|pages=603–614|s2cid=168043081|url=https://engagedscholarship.csuohio.edu/cgi/viewcontent.cgi?article=1112&context=bus_facpub|url-access=subscription}}</ref>