<i>Insofar as preference depend on nudges&#x2F;framing -- that is, insofar as preferences aren&#x27;t even uniquely defined -- then you need to actually test the various nudge.</i><p>The airlines already have the ability to &quot;nudge&quot; and &quot;frame&quot;; the big three legacy carriers in the US all have flight-search interfaces which show you the different types of fares and highlight the conveniences that come with them.<p>People still just pick whichever one is cheapest and then complain about how awful it is. Two of the three big legacies have, as I noted, already begun the rollout of ultra-bare-bones no-conveniences fares for this very reason: they have the data and they know what works.<p><i>I think everything else you&#x27;ve written is also consistent with my primary claim, which is that we should not legislate seat sizes. I appreciate the other info, though.</i><p>I think we are at or near the point where seat pitch and size will need to be legislated, not for comfort but for safety. As I understand it, many safety tests (such as verifying emergency evacuation within a required minimum time) on airliners are already conducted using cabin arrangements with significantly higher pitch than is typical for actual aircraft in service. And as seat pitch decreases various flying-induced medical conditions either become more likely or are exacerbated.<p>And when something is affecting safety, I will absolutely support legislation to deal with that.