The Convenience Cost of Portion Sizes

The folks at the Center for Science in the Public Interest has published a story on Coca Cola's new 7.5 oz cans. Credit where credit is due: it's both good business and good from a public health perspective to offer top-of-the-food-pyramid foods like Coke in smaller portion sizes. But CSPI isn't congratulating Coke on a job well done.  On the contrary, the non-profit points out that the unit-price on the new can is a significant mark-up relative to other sizes - about $2.13 per quart compared with $.89 - $1.33. Presumably the mark-up more than covers the additional cost of materials and the advertising costs incident to introducing a new product.

Is this a big deal? Is this something to get upset over? For one thing, Coke has been selling 8 oz cans at similarly inflated prices for years, so this is nothing new. For another, unit prices are printed (albeit in much smaller type) on the price-tag at the grocery store, so it's not like this is some big secret. Nonetheless, I can relate from personal experience (teaching classes on smart shopping for folks on SNAP and similar programs) that there are many people who do not understand or use the unit prices when shopping. I'm not sure what the best way to remedy this is (better basic math education? larger unit-price labels?), but as things are now, there's a lot of people who will probably be buying this product without realizing that they're paying what is in essence a portioning tax levied by Coca Cola.