Libertarian paternalism is an oxymoron

Remember those Sci-Fi movies from the '50s where the mad scientist, who only had the good of the world at heart and proceeded with his experiments despite much warning, winds up on his knees crying out to the sky "It wasn't supposed to be like this! This isn't what I wanted!"

Here's Richard Thaler on Mayor Bloomberg's ban on soda:

To state the obvious: a BAN is not a NUDGE.The opposite in fact. So don't blame Bloomberg's ban on large soda cups on us.
— Richard H Thaler (@R_Thaler) May 31, 2012

To which Justin Wolfers replied:

.@R_Thaler Disagree. Bloomberg's not banning Soda. Indeed, the big cup still exists--it's two little ones. So this IS really a nudge.
— Justin Wolfers (@justinwolfers) May 31, 2012

There isn't much distance from nudge to shove, especially when preference heterogeneity keeps nudgers from recognizing when they're shoving. Justin doesn't see it as too costly, likely because he isn't a soda-fan either. So how could it be costly? A religious nudger could similarly see it as pretty costless to encourage at-home parenting by banning having a nanny employed more than 3 days a week; a parent could always opt-out by hiring a second nanny.

Should we blame Thaler? Here's what he had to say two years ago when pressed on whether his libertarian paternalism wouldn't lead to bans and harder paternalism:

In short, the risk of the slippery slope appears to be a figment of Professor Whitman’s imagination, and clear evidence of his bathmophobia. To be fair to him, this phobia is hardly unique to him and Professor Rizzo. Slope-mongering is a well-worn political tool used by all sides in the political debate to debunk any idea they oppose.
...
Instead of slope-mongering we should evaluate proposals on their merits. (We devote a chapter of Nudge to an evaluation of the choice architecture used in Sweden’s social security experience.) Helping people make better choices, as judged by themselves, is really not a controversial goal, is it?

For all the protests that "nudge" was supposed to have strong opt-out provisions, it was awfully predictable that it wouldn't turn out that way in practice. I don't know how much time Thaler spent  working to ensure choice was preserved in his proposed choice-preserving architecture, but he did spend a bit of time telling libertarians that this sort of thing couldn't happen.

I still like my old review of Nudge, in which I proposed some nudges at the ballot-box:

While Sunstein worries about our decisions over investment plans or our weakness of will at the buffet table, I worry about our decisions at the voting booth. We vote infrequently, there’s no feedback from our personal voting decision to any policy outcome (unless you happen to hit Lotto by breaking a tie), the voting decision is complex and we may have little grasp of the issues at stake let alone our own positions on those issues. In my own research, I’ve found that only about half of voters in 2005 could place National, United Future, and Labour correctly on a left-right spectrum, for example, and that individuals’ political knowledge independently affects their policy and party preferences even after controlling for income, education, race, employment, gender, and other demographic characteristics. And so I think we (by which I mean you) need a nudge. Under my libertarian paternalistic voting system, your electoral enrolment would be linked to your census details. You’d then answer a brief questionnaire when entering a computerized voting booth, and I’d tell you, through the computer’s algorithms, for whom you should vote. Trust me: I’d be choosing the option that really would be best for you, if you only understood all of the policies supported by each of the parties and had a PhD economist’s understanding of the likely effects of these policies. You’d still be free to pick some other candidate or party, but you’d have to first reject the default choice I’d pick for you. The remaining options would then be presented in an order designed to maximize the chances of your choosing the next best option.

I trust that you find this kind of scheme repugnant. I’d find it great, so long as I got to be the choice architect. But opinions surely would vary, and I’d surely oppose the scheme if anyone other than me got to be the architect. The problem is that most of the arguments against my scheme cut similarly against Sunstein’s. More worrying, Sunstein seems pretty happy to blur the line between nudges and shoves: increasing cigarette taxes to discourage smoking is surely paternalistic, but is a bit stronger than a nudge. And, honestly, even the choice preserving nudges, like cars that nag you about the petrol you could save by easing up on the pedal, sound thoroughly unpleasant: I’d be nudged into learning enough automotive electronics to cut the right wires.

Update: It's occurred to me that I can't assume that everybody in the world has read the brilliant piece that started all this: Sunstein and Thaler's "Libertarian Paternalism Is Not An Oxymoron". Restricting it to choice of defaults, it's pretty tough to fault their argument. Except it never gets restricted to choice of defaults, now, does it?