Then there is the question of who consents. Camilla Nevill of the Economics Endowment Foundation says that trials are often agreed to and conducted by schools. Trying to persuade every parent to agree explicitly to the trial “decimates” the number of participants, she says.
Is this ethically troubling? At first glance, yes. But there is a risk of a double standard. Without the EEF funding, some schools would adopt the new teaching approach anyway. It is only when a researcher proposes a meaningful evaluation that suddenly there is talk of informed consent.
--Tim Harford on unethical withholding of randomized controlled trials. HT: Chris Blattman