Anders Sandberg writes here about how the finish-the-plate bias can lead people to overeat, simply because food comes in larger packages (which, in turn, presumably arises because food is so cheap to produce). Anyway, this reminds me of an insight I had several years ago which I used to tell the students in my decision analysis classes. They were always skeptical but maybe now with research behind me on this, they’ll believe me.
Anyway, here goes:
When I was younger, people used to complain about candy bars getting smaller and smaller. (For example, Stephen Jay Gould has a graph in one of his books showing the size of the standard Hershey bar declining from 2 ounces in 1965 gradually down to 1.2 ounces in 1980, and for that matter I can recall tunafish cans gradually declining from 8 ounces to 6 ounces.) And I remember going to the candy machine with my quarter and picking out the candy bar that was heaviest–I don’t remember which one–even if it wasn’t my favorite flavor, to get the most value for the money.
But now I realize that, rationally, candymakers should charge more for smaller candy bars. The joy from eating the candy is basically discrete–I’ll get essentially no more joy from a 1.7-ounce bar than from a 1.4-ounce bar. But the larger bar will be worse for my health (no big deal if I eat just one, but with some cumulative effect if I eat one every day, similarly with the sodas and so forth). And, given the well-known fact that nobody can eat just part of a candy bar, I get more net utility from the small bar, thus they should charge more.
Actually, this is a growing trend in retail food marketing. "100 calorie snack packages" of cookies and crackers are quite popular. If you work out the price per ounce (or if your state requires these to be posted on the shelf), you'll quickly see that grocers are charging a lot more per ounce for these packages.
As a cheap skate who needs to limit his intake of some of these foods, I've taken to buying the large economy size and then repackaging the goodies in smaller snack sized bags.
If you look at a bag of hershey's miniatures, you will notice that you do pay more per ounce for the miniature candy bars than their regular-sized counterparts.
taking this to the extreme, candy companies should ditch all the additives and go straight for pure cocoa which has health benefits that is provided this site is true:
http://www.acu-cell.com/choc.html
it's funny I was going to post about chocolate as an anti-oxidant, anti-depressant, etc and make a case for the larger bar bringing more joy, but when I searched for some research on that matter I ended up at the above link. Ahh how rebuttals can change you.
This really isn't a comment on the post, rather the full plate of your blog page. Your blog is becoming large enough that it's becoming a hassle to load and scroll up & down. If you can start a page 2, it'd be a big help for readers like me, who work with older computers.
Sorry to bother,
jsh
I've read somewhere (Bill Bryson?) that the Hershey bar shrank, because Hershey himself wanted to keep it costing a dime. But eventually, they gave up, so it grew again.
Andy, aren't you contradicting yourself by saying on one hand that you'd trade off quality for quantity (by choosing the heaviest bar at the candy machine) and on the other that you'd get no more utility from a 1.7 vs 1.4 oz bar?
You're referring to yourself at two different ages (with two very different sets of preferences)…Clearly you were at some point willing to forgo enjoying your favorite candy bar just to have a little more chocolate.
It's precisely the problem of maximizing profit given heterogeneous consumers that makes it not entirely obvious that it would be "rational" for candy makers to charge more for smaller bars.
Sure, if the candy makers could effectively price discriminate they would charge more per ounce for a 1.4 than a 1.7 oz bar to those who would pay it. But candy makers can't price discriminate, so the next best thing might be for them to create products targeted more homogeneous subgroups of consumers. Then they could potentially charge more per ounce to some groups than to others. This is probably one of the reasons something like Hershey's miniatures costs more per ounce than Hershey's regular bars. The two products don't have identical consumer profiles.