Title,Url,Last update date,Published at,First registered on,RCT_ID,DOI Number,Primary Investigator,Status,Start date,End date,Keywords,Country names,Other Primary Investigators,Jel code,Secondary IDs,Abstract,External Links,Sponsors,Partners,Intervention start date,Intervention end date,Intervention,Primary outcome end points,Primary outcome explanation,Secondary outcome end points,Secondary outcome explanation,Experimental design,Experimental design details,Randomization method,Randomization unit,Sample size number clusters,Sample size number observations,Sample size number arms,Minimum effect size,IRB,Analysis Plan Documents,Intervention completion date,Data collection completion,Data collection completion date,Number of clusters,Attrition correlated,Total number of observations,Treatment arms,Public data,Public data url,Program files,Program files url,Post trial documents csv,Relevant papers for csv Anchoring bias in markets,http://www.socialscienceregistry.org/trials/3402,"March 18, 2021",2021-03-18 11:08:50 -0400,2018-10-16,AEARCTR-0003402,10.1257/rct.3402-2.0,Konstantinos Ioannidis ioannidis.a.konstantinos@gmail.com,completed,2018-10-22,2018-12-30,"[""other"", ""Anchoring bias"", ""double auction"", ""bilateral bargaining""]",Netherlands (Europe),Theo Offerman (t.j.s.offerman@uva.nl) University of Amsterdam; Randolph Sloof (r.sloof@uva.nl) University of Amsterdam,"D01, D02, D91","","In a laboratory experiment, we investigate whether the information revealed during market participation reduces the anchoring bias observed in individual decision making. We control the amount of information available in the market using 3 different market settings: a double auction, bilateral bargaining, and a control treatment in which a good different from the anchored one is traded. Anchors are created randomly for each individual subject by rolling a 10-sided die twice; using a median split subjects are divided into a low anchor group and a high anchor group. The main question of interest is whether the difference in the willingness to pay between the low anchor and the high anchor group observed before market participation is eliminated after the market participation.","","","",2018-10-22,2018-12-30,"Anchoring is attempted by the following Yes/No question: Would you sell the good back to the experimenter for X€? X is created randomly by rolling a 10-sided die twice. After the anchoring question, participants interact in a market: either a double auction, bilateral bargaining, or in a double auction for a different good (control treatment).",Willingness To Accept (WTA) both before and after the market participation. The low and the high anchor group will be determined by a median split. We will also compare the difference in WTA before and after market experience between the highest quartile and lowest quartile of the anchor distribution.,"Difference in WTA between the low and high anchor group, both before and after market participation.","Probability of a trade, Speed of a trade, Price of a trade","Probability of a trade = ratio of agreed trades over all possible trades Speed of a trade = seconds until trade is agreed (Only for realized trades) Price of a trade = agreed price (Only for realized trades)","We anchor subjects with a random price and compare their WTA for a good before and after participating in a market. Three types of market settings are studied: a double auction, bilateral bargaining, and a double auction for a different good.","Our experiment consists of 3 Phases. In Phase I, we anchor subjects' with a random price and elicit their WTA for a good. The anchoring happens via a Yes/No question of the type: ""Are you willing to sell the good to the experimenter for X€? The X is determined by rolling a 10-sided die twice and making a price out of the rolls (eg rolls of 6 and 7 give price 6.7€). In Phase II, subjects participate in a market. . Three different market settings are studied. In the Double auction treatment, participants are grouped in groups of 8 with 4 buyers and 4 sellers and participate in a double auction (for the same anchored good). In the Bilateral bargaining treatment, participants are grouped in pairs (1 buyer and 1 seller) and negotiate a trade. In the control treatment, participants take part in a double auction for a different good. In Phase III, we elicit WTA for the good again. After the first two sessions a manipulation check will be performed to verify successful inducement of the initial anchor.","For each individual subject, the random anchor is obtained from two (10-sided) die rolls.","Subjects are randomly assigned treatment market setting before a session starts. Within each market setting, a median split on the random anchors defines the Low Anchor and the High Anchor groups.",480 participants from 30 sessions with 16 participants in each.,480 participants,"160 participants in the Double Auction treatment (80 in Low Anchor group and 80 in High Anchor Group) 160 participants in the Bilateral Bargaining treatment (80 in Low Anchor group and 80 in High Anchor Group) 160 participants in the Control treatment (80 in Low Anchor group and 80 in High Anchor Group) (We may encounter problems with the size of our subject pool. If we cannot manage to have 480 subjects, we will have less in the Control treatment.)","With our sample and assuming a standard deviation of 3.5 (based on an in-classroom pilot session), the Minimum Detectable Effect size is 1€. Defining the effect size as the difference in means divided by the pooled standard deviation, the percentage is 28%.","Name: Ethics Committee Economics and Business (EBEC), University of Amsterdam Approval_number: EC 20180926020919 Approval_date: 2018-09-26 ",None,2018-11-16,true,2018-11-16,98 trading groups (20 Double Auction sessions + 78 Bilateral Bargaining sessions),false,316 subjects,"160 participants in the Double Auction treatment (80 in Low Anchor group and 80 in High Anchor Group) 156 participants in the Bilateral Bargaining treatment (78 in Low Anchor group and 78 in High Anchor Group) * Given our null result of anchoring, the control treatment was not run.",true,https://github.com/KonstantinosIoannidis/Anchoring/tree/master/Data,true,https://github.com/KonstantinosIoannidis/Anchoring/tree/master/Stata,"","Abstract: We test whether markets are needed to mitigate the effects of anchoring on peoples' preferences. We anchor subjects by asking them if they are willing to sell a bottle of wine for a transparently uninformative random price. We elicit subjects' Willingness-To-Accept for the bottle before and after the market. Subjects either participate in a small or a large double auction market. The variance in subjects' Willingness-To-Accept shrinks within trading groups. Our evidence supports the idea that markets have the potential to mitigate a bias. However, the market is not needed: our anchoring manipulation failed in a large sample. Citation: Ioannidis, K., Offerman, T., & Sloof, R. (2020). On the effect of anchoring on valuations when the anchor is transparently uninformative. Journal of the Economic Science Association, 6(1), 77-94. URL: https://link.springer.com/article/10.1007/s40881-020-00094-1 "