One of my worries is that embarking on policy for behavioural-justified reasons puts us quickly on the path to hard coercion when the behavioural targeting fails to achieve the desired end. Politics doesn’t handle sunk costs well. So it’s easy for “We think X failing leads to bad outcomes on Y, so we’ll try B non-coercive policy” to turn into “We have failed to achieve our common goal of Y and so stronger measures are warranted.” 

Examples? Look at how quickly “Oh, imperfect information is what makes people smoke too much” turned into “Let’s force people to quit smoking by eradicating tobacco by 2025”. All kinds of slippery slopes in paternalistic policy. 

I think they exaggerated quite a few things so I’ve queued up a few posts on those issues. It is really nice to see them put the views of BE’s opponents so strongly, though. And, as you say, some of the points are well made.

If it’s overt coercion, then it is not a behavioural measure, it is regulation.  The whole point of behavioural measures is that they encourage but do not enforce behaviour which is thought to be in the individual’s best interest. 

Their point that regulators cannot be certain that they know the individual’s best interest any better than the individual does is far stronger.