An optional charge where the default choice is to pay it is the sort of thing Sunstein and Thaler propose, a nudge in the direction of doing what those responsible believe, possibly correctly, that most of those nudged would want to do if they took the time to think about it. But the people constructing the choice architecture know what result they want to get, they believe they are doing good and so not constrained by what they themselves would consider proper principles of morality and honesty in a commercial context, so it is very easy to make the "wrong" choice more and more difficult and obscure until what is optional in theory becomes mandatory in practice.Add in ambiguity about what's good enough as opt-out provision and nudge seems likely to drift quickly to shoves.
Cornell's Brian Wansink and David Just worry that the large soda ban won't just be ineffective:
We've dedicated our research careers to helping people eat better, contributing to Smarter School Lunchrooms, 100-calorie packs, and the 2010 Dietary Guidelines. We fear that this ban on large soft drinks will be a huge setback to fighting obesity for two reasons: 1) unless it succeeds, it will poison the water for better solutions, and 2) it won't succeed.This might be the case in New York, where this ban is looking particularly unpopular. For popular but ineffective bans, I worry we instead make more heavy-handed regulation more likely when the softer touch fails. Adam Ozimeck asks* current paternalists what measures they'd deem too draconian if implemented sometime down the line; if we look at the slippery slope in tobacco regulation, it's the right question to ask. Just don't expect the goalpoasts to stay put.
First, consider the McLean Effect. McDonald's launches the visible and controversial low-calorie hamburger. It failed, becoming a byword for restaurants for the next 15 years. No one would dare introduce low-calorie fast-food offerings because "Look what happened to the McLean."
Banning larger sizes is a visible and controversial idea. If it fails, no one will trust that the next big—and perhaps better—idea will work because "Look what happened in New York City." It poisons the water for ideas that may have more potential.
* Look for the post "A Challenge for Paternalists", 5 June.