University of Chicago law profesor Cass Sunstein blogs in defense of libertarian paternalism:

Becker and Posner make some nice points against those who like government bans and mandates (though Posner, interestingly, defends the ban on trans fats in New York City restaurants; libertarian paternalists would disapprove of any such ban). But libertarian paternalists do not mean to allow government to forbid the triumph of the supposed "weaker" self over the supposedly stronger one. If people want to eat a lot of candy and ice cream, or refuse to save for their retirement, that is their right. Far from neglecting the bounded rationality of government officials, libertarian paternalists emphasize government error as a strong reason for respecting freedom of choice.

What libertarian paternalists add is that the opposition between "individual choice" and "government" is confusing and unhelpful when government is inevitably establishing default rules that govern outcomes if choices haven't been specifically made -- and that influence people's choices in any case. A key point, then, is that private and public institutions can't possibly avoid a form of paternalism, so long as they establish default rules and starting points. (For some reason, economists in particular seem not to understand this point.) The question is how to make those starting points as good as possible, while also preserving free choice.

For more on this subject, see Sunstein's paper with Richard Thaler, "Libertarian Paternalism Is Not an Oxymoron," and Gregory Mithcell's response, "Libertarian Paternalism Is an Oxymoron."