I do not see why experimentation is impossible if we are in a position where there literally is no alternative other than doing 'experiments' except refusing to address the results and change tactics except under extreme political pressure. Things like 'we believe if taxes are lowered on businesses, it will result in them hiring more workers', after it has been tried for 30 years and has resoundingly shown to be a collassal untruth, actively destroying the middle class and leading to tremendous instability even among those who do remain employed, at least if we could say it was an experiment and we were uncertain of the outcome, we could say 'well that didn't work let's try something different' instead of it being a political battle fueled by people just trying to trick others into thinking that reality is different from what it is.

In a situation that affects so many people, it may seem unwise to do experiments and try things where we can not say with certainty what effects they might have, though we admit they may be substantial. The ethics are very dim on that front. But the alternative has to be considered. We do not have 'generally accepted treatment' to turn to and rely on. We only have other experiments, albeit while not calling them experiments and not treating them as if their outcomes are in doubt, simply forging ahead with blinders on. I can't imagine an argument that would justify that as more ethical than earnestly doing experiments.