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No Bubbles in the City. An Experiment with Professional Traders
Last registered on October 24, 2019


Trial Information
General Information
No Bubbles in the City. An Experiment with Professional Traders
Initial registration date
February 03, 2019
Last updated
October 24, 2019 4:45 AM EDT
Primary Investigator
University College London
Other Primary Investigator(s)
PI Affiliation
PI Affiliation
Additional Trial Information
In development
Start date
End date
Secondary IDs
We examine how professional financial traders behave in two classic laboratory market environments. First, traders trade an asset with a declining fundamental value (Smith, Suchanek, & Williams, 1988) while receiving private information about the asset's value. Second, traders make choices in a ``guessing game'' with peers (Nagel, 1995) as well as within our novel ``individual guessing game'' framework. We also collect data on cognitive factors (IQ and CRT), behavioral factors (risk, confidence, and digit-ratio), and personality traits (e.g. Big 5). This is compared against data from undergraduate students. In accordance with previous studies, undergraduates overprice the asset (a ``bubble'') and, in the guessing game, make choices consistent with different levels of strategic reasoning. In contrast, traders trade at prices that closely reflect the asset's declining fundamental value and make choices that suggest higher levels of strategic reasoning than the levels of the students. Professional traders are also better than undergraduates in aggregating private information through trading activity. In addition, choices from our individual guessing game can decompose a subject's own level of strategic reasoning from their belief about the population's level of reasoning. Our data show that traders anticipate that their opponents will have higher levels of strategic reasoning than do that of students.
External Link(s)
Registration Citation
Cipriani, Marco, Antonio Guarino and Ryan Kendall. 2019. "No Bubbles in the City. An Experiment with Professional Traders." AEA RCT Registry. October 24. https://doi.org/10.1257/rct.3853-2.1.
Former Citation
Cipriani, Marco et al. 2019. "No Bubbles in the City. An Experiment with Professional Traders." AEA RCT Registry. October 24. http://www.socialscienceregistry.org/trials/3853/history/55780.
Experimental Details
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
We have two primary outcomes we are interested in. First, do the traders behave differently (better) in the market experiments than do the students? Second, based on a battery of individual-level tests conducted after the market experiments, which cognitive or non-cognitive trait best predicts performance in the experimental market.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
We are studying behavior in market experiments across different groups: Professional financial traders and undergraduate subjects. We are also studying for differences in individual-level behavior across groups (e.g. IQ).
Experimental Design Details
Randomization Method
Randomization is always carried out by computer programs.
Randomization Unit
We will be looking at, both, individual level choices (e.g., scores on tests and personal earnings) and group level choices (e.g., average price per period and comparison across population groups).
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
We have 56 subjects in each of the two groups (for 112 total subjects).
Sample size: planned number of observations
Each subject makes make choices in the experiment.
Sample size (or number of clusters) by treatment arms
Our treatment variable is the two different population groups.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
UCL Research Ethics Committee
IRB Approval Date
IRB Approval Number
Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)