Affordable Access

Publisher Website

A new perspective on the issue of selection bias in randomized controlled field experiments

Authors
Journal
Economics Letters
0165-1765
Publisher
Elsevier
Volume
124
Issue
3
Identifiers
DOI: 10.1016/j.econlet.2014.06.001
Keywords
  • Field Experiments
  • Selection Bias
  • Randomized Controlled Trials
  • External Validity

Abstract

Abstract Many randomized controlled trials require participants to opt in. Such self-selection could introduce a potential bias, because only the most optimistic may participate. We revisit this prediction. We argue that in many situations, the experimental intervention is competing with alternative interventions participants could conduct themselves outside the experiment. Since participants have a chance of being assigned to the control group, participating has a direct opportunity cost, which is likely to be higher for optimists. We propose a model of self-selection and show that both pessimists and optimists may opt out of the experiment, leading to an ambiguous selection bias.

There are no comments yet on this publication. Be the first to share your thoughts.