#MTRP: Mechanical Turk Replication Project

about the project


What exactly are we doing? We have selected 41 experimental studies in the social sciences conducted on MTurk published in the Proceedings of the National Academy of Science (PNAS) in 2015-2018. We will replicate 26 of these, and all studies have a positive probability of being chosen for replication. The 41 papers were objectively chosen because they were published in this high-profile journal in this time period, they are online studies involving subjects from Amazon Mechanical Turk, they share a common structure in testing a treatment or interaction effect within or between subjects, and they test at least one clear hypothesis with a statistically significant finding. We plan to conduct the replications starting in January 2022 and throughout the spring of 2022.

Replication procedure: We will carry out the data collection based on having 90% power to detect 67% of the effect size reported in the original study (with the effect size transformed into the Cohen's d, to have a common standardized effect size measure across all studies). The criteria for successful replication is an effect in the same direction as the original study and a p-value < 0.05 (in a two-sided test). This is the replication outcome traders are betting on - but in the paper we will also include other replication criteria.

Choosing what to replicate: We will run a decision market where we will ask participants to help us choose which studies to replicate. All studies will have a positive probability of being chosen for replication. Please see the tab “Decision Markets” for more information. In short, decision markets function similarly to prediction markets in that traders bet on the replication outcome, but not all studies will actually be replicated. The selection of the 41 studies does not reflect any subjective belief of ours about whether or not these studies were especially likely to replicate.

who runs this project?


The project will be conducted by research teams from CalTech, Harvard University, National University of Singapore, Stockholm School of Economics, University of Amsterdam, University of Innsbruck, University of Pennsylvania, and University of Virginia. In particular, the following people are involved...

Colin Camerer
Colin Camerer
California Institute of Technology
Yiling Chen
Yiling Chen
Harvard University
Anna Dreber
Anna Dreber
Stockholm School of Economics
Teck Hua-Ho
Teck Hua-Ho
National University of Singapore
Felix Holzmeister
Felix Holzmeister
University of Innsbruck
Suzanne Hoogeveen
Suzanne Hoogeveen
University of Amsterdam
Jürgen Huber
Jürgen Huber
University of Innsbruck
Michael Kirchler
Michael Kirchler
University of Innsbruck
Lawrence Jin
Lawrence Jin
National University of Singapore
Taisuke Imai
Taisuke Imai
LMU Munich
Magnus Johannesson
Magnus Johannesson
Stockholm School of Economics
Alexander Ly
Alexander Ly
University of Amsterdam
Benjamin Mandl
Benjamin Mandl
Stockholm School of Economics
Dylan Manfredi
Dylan Manfredi
University of Pennsylvania
Gidi Nave
Gidi Nave
University of Pennsylvania
Brian Nosek
Brian Nosek
University of Virginia
Thomas Pfeiffer
Thomas Pfeiffer
Massey University
Alexandra Sarafoglou
Alexandra Sarafoglou
University of Amsterdam
Rene Schwaiger
Rene Schwaiger
University of Innsbruck
E.-J. Wagenmakers
E.-J. Wagenmakers
University of Amsterdam
Viking Waldén
Viking Waldén
Stockholm School of Economics