A judge has overruled Mayor Bloomberg's soda ban, calling it "arbitrary and capricious." So New York City's ban on large sugary beverages, meaning more than 16 oz. servings, is basically dead. This is a big win for Big Gulp Libertarianism, which derided the government soda ban as Nanny State tyranny, taking away individual's freedom to make their own rational choices. But you know what else is arbitrary, capricious, and erodes individual freedom of choice? Marketing. Every food package you will ever encounter was designed to limit the exercise of your free will. Selling someone else a 64-ounce cola may be a rational individual decision. But buying a 64-ounce cola is not quite an act of unfettered free choice.

I spent a month or so last summer living in Rome, which meant cooking and shopping in Rome (a great pleasure) and becoming that timeless figure of comedy, the Americano nel supermercato. That meant everything I bought in a bag, packet, or can came in a smaller bag, packet, or can than I'm used to. A can of tuna, say, was a little more than half the size of an American tuna can (80 grams instead of 140+). And within 24 hours of getting off the plane, I had adjusted to thinking of that as a standard can of tuna. When I flew back to the United States and walked into an American supermarket, I switched back. But I didn't constantly open a second can of tuna in Rome so that it would be the size of a "real" can. There's no such thing as a "real" size for a can of tuna. I just worked with the set of units I was given, like everyone does. It's not that I decided I wanted exactly 80 grams of fish. But by the same token, I don't "want" exactly 142 grams of fish at a time when I'm in America. That's just the size the can comes in, and so when I open a can I try to use the amount of tuna that's in it. I didn't decide that I wanted this or that amount.

Opponents of the Bloomberg ban say that people will just order two (or four) 16-ounce sodas to get around the ban. The judge says the same thing. In fact it seems like such common sense that it's a joke: how ridiculous not to expect people to buy two sodas instead!

Please. No one was going to do that. That is not how the world works at all.

No one just naturally decides on their own that they want 32 or 64 ounces of soda. You don't go into the 7-11 and think, "Man, I need 64 ounces of something cold, 'cause there isn't nearly enough pressure on my bladder." The idea of buying something that size has to be suggested to you, and the suggestion has to be framed so the decision feels natural. If there were no 64-ounce sodas on sale, you wouldn't think the 16-ounce soda looked inadequately small. It wouldn't even occur to you.

Seriously: before people started buying Big Gulps, were customers buying two or three sodas at a time because the available sizes did not satisfy their thirst? Does anyone actually believe that the super-sized drinks were created to respond to customer demand? If you do, I have some shares of Lehman Brothers to sell you. Those sizes were invented to create customer demand. It's better for the seller to sell larger amounts of the (cheap and government-subsidized) sugar water, so they created a set of packaging choices where 16 ounces went from "extra-large" to "medium" or "small." And they frame super-sizing your drink as a bargain. Bingo! Illusion of choice. You get to experience 7-11's corporate strategy as your natural exercise of free will.

If you're not willing to believe that, let me point out a basic fact. There are professional stage magicians all over this country who can "read your mind" by identifying the number/playing card/primary color/etc. that you think of when they ask you. They don't do this with trick decks of cards: it still works with numbers, colors, and so on. They do the trick by choosing the number or color for you. This is so easy that a non-trivial number of people make a living doing it. You never know they choose for you. You experience it as your own choice. But the trick, called the "force," works effectively and reliably. If you ever want to ruin a magic show, just write down the second number that comes into your head after the magician asks you to write down the first number that comes into your head. The first number that comes into your head is the one the magician picked for you. (But if you ever ruin a magic show, you are using your knowledge for evil and I disown you.)

We like to think of a magician's force as just something that happens on stage in Vegas. But it happens all the time. We all fall for the Jedi mind trick every day, and when someone points it out to us we angrily insist that it was our own idea all along: those are not the droids we were looking for! It's simply too uncomfortable to think that many of the ideas that seem to appear independently in our head have actually been placed there by others as we happened by. If we're that easily suggestible, what about our free will? Science's answer seems to be: what about your free will, sunshine? Where did you see it last?

If you want to strike a blow for the freedom of human self-determination, fighting the soda ban is a sucker's game. All you're fighting for there is the right of corporate entities to manipulate your behavior, and your personal right to be their sucker. If what you're interested in, however, is fighting to preserve your illusion of self-determination, your right not to notice that your free will isn't 100% free or 100% yours, then you go right ahead and fight that evil nanny state, brother. But don't expect the rest of us to hail you as a champion of liberty. You're perfectly free to delude yourself. Enjoy your visit to New York.