To conduct randomized field experiments while easing the disutility of subjects and concerns of practitioners, I empirically study the ethical concerns held by potential subjects. In the first survey, approximately 2,000 respondents are asked whether they recognize ethical issues in six existing experiments. Among these six experiments, an early childhood intervention is recognized as the most acceptable, while a charitable fund-raising experiment using lotteries is recognized as the least acceptable from an ethical perspective. To investigate methods to ease such ethical concerns, I conduct the second survey in which respondents are randomly assigned to four groups. I find a nonsignificant impact of changing the research methodology from a randomized experiment to an uncontrolled before–after study. However, ethical concerns significantly increase when informed consent is not enough or when subjects are randomly sampled. These findings support an experiment with agreed-upon participants, although it may limit the external validity of the experiment.
Keywords: Ethical issues, Field experiments, Online surveys, Randomized controlled trials
