Because it’s easier to get the ice cream, of course. From Brian Wansink’s Food Think:
One cafeteria tested (how much effort people will go to to eat ice cream) by leaving the lid of an ice cream cooler closed on some days and open on other days. The ice cream cooler was in the exact same location, and people could always see the ice cream. All that varied was whether they had to go through the effort of opening the lid in order to get it. Even that was too much work for many people. If the lid was closed, only 14% of the diners decided it was worth the modest effort to open it. If the lid was open, 30% decided it was ice cream time.
Some readers may wonder why a store owner would ever leave the lid on an ice cream freezer open? Would the extra cost of the energy (not to mention the general environmental unfriendliness of such a strategy) be worth the extra ice cream sales? Maybe not for a typical freezer. But Wansink says there are some in Europe that keep ice cream frozen from the bottom, allowing owners to lose the lid. Any readers seen or shopped at these freezers before?
Hat tip: Tom Vanderbilt.
Nudge blog 
March 26, 2009 at 6:13 am |
These freezer are widely available everywhere. In the US they’re called “coffin chests.” Cold falls so the chests stay cold. Of course, you wouldn’t leave the top open in 100 degree temps.
March 26, 2009 at 12:41 pm |
I’ve shopped at those before, in fact they are very common in Germany, and you sometimes see them in the UK.
It actually changes depending on which produces are displayed – ice cream cenerally is displayed in freezers without a lid, while chicken generally isn’t. The location seems important too, as icream is generally closer to the check out.
Seems to be linked to impulse buys (less likelyhood for a lid, to ecourage them) and planned buys where the cost-benefit ration would be different/less favourable.
March 26, 2009 at 3:28 pm |
I saw them all over Poland where lody is a national treasure. The nudge almost always worked for me.
March 26, 2009 at 3:53 pm |
While the effort is minimal, it takes enough mental energy to focus my attention on what I’m doing and remind me that the item is unhealthy. It also makes my ice-cream eating feel more conspicuous.
I wonder if the phenomenon would hold if the items in the freezer were healthy.
March 26, 2009 at 8:31 pm |
further research is needed to then determine:
which cooler would sell more ice cream? the lidless freezer? or the unnecessary-lid-left-open-all-the-time freezer?
March 29, 2009 at 10:53 pm |
I agree with Liz…could it be because people don’t want the attention of opening and closing the lid (possibly with a loud thud)? Maybe they are just trying to avoid everyone watching them pig out on ice cream?
March 29, 2009 at 10:56 pm |
I agree with Liz…maybe people don’t want the attention of opening and closing the lid (sometimes with a loud thud)?
Maybe they just don’t want people knowing when they are shoving ice cream in their face? With the door open they can sneak in and grab their ice cream sandwich without people seeing them!
April 12, 2009 at 6:34 am |
Another possibility is the visibility of the ice cream… I think people often go for impulse buys because they *see* the item. A transparent lid of a thick-enough material would reduce wasted energy while still keeping the ice cream clearly visible.
Make it a sliding lid and you could also eliminate the “attract attention with the big lid hinged up” and the “close with a loud thud” deterrents.
April 12, 2009 at 6:40 am |
Well, I see the quote says “people could always see the ice cream”. Without seeing a photo of the exact freezer involved, I assume it is not one with a transparent lid as I suggested, since I’ve never encountered one like that myself.
So presumably that quote meant something else, that is more along the lines of “could always see signs promoting the ice cream”, “could always see the case the ice cream was in”, etc…?
If not, never mind.
December 24, 2009 at 2:40 pm |
with high frequency and type of people who like ice cream, it is obvious the lid will be useless most likely it will be left open most of the time (considering the supermarket situation) unless you hire a worker to open and close the lid all the time, if a lot of people come to take ice cream even that will allow cold air to escape at high rate, So then the lid was USELESS at that.