Baseball cards deliver poor returns on investment

Youngsters who saved their baseball cards from the 1950s -- as my own father did -- found themselves sitting on a goldmine big enough to make a sizable contribution toward a college education.

People who bought baseball cards from the 1980s were less fortunate. The Wall Street Journal (subscription required) reports that "Two things worked against these investments. The first is that trading cards were too popular in the 1980s. Card companies printed a lot of them and young collectors kept them in pristine condition. Thus they have no relative scarcity of the kind that makes famous ones like Mickey Mantle's 1952 Topps card so valuable."

It's a classic case of reflexivity: Baseball cards became so collectible that they didn't have any value. That rule applies to nearly every product that is marketed, and it's why collectible plates offered in infomercials and Parade magazine advertisements have generally made such abysmal investments.