Title

Selective Trials: A Principal-Agent Approach to Randomized Controlled Experiments

Author(s)

Sylvain Chassang Sylvain Chassang (Princeton University)

Gerard Padro i Miquel Gerard Padro i Miquel (London School of Economics)

Erik Snowberg Erik Snowberg (Caltech)

Abstract

We study the design of randomized controlled experiments in environments where outcomes are significantly affected by unobserved effort decisions taken by the subjects (agents). While standard randomized controlled trials (RCTs) are internally consistent, the unobservability of effort provision compromises external validity. We approach trial design as a principal-agent problem and show that natural extensions of RCTs which we call selective trials can help improve the external validity of experiments. In particular, selective trials can disentangle the effects of treatment, effort, and the interaction of treatment and effort. Moreover, they can help experimenters identify when measured treatment effects are affected by erroneous beliefs and inappropriate effort provision.

Creation Date

2010-08

Section URL ID

ET

Paper Number

wp003.pdf

URL

https://www.sylvainchassang.org/assets/papers/selective_trials.pdf

File Function

Jel

C81, C93, D82, O12

Keyword(s)

randomized controlled trials, selective trials, blind trials, incentivized trials, marginal treatment effects, mechanism design, selection, heterogeneous beliefs, compliance

Suppress

false

Series

10