It seems like just yesterday a kid’s birthday party could be put over the top by the appearance of a regular old birthday clown.  Some of the kids would be entertained, most would be petrified, and the party would be a success regardless.  These days, writes Katherine Rosman of the Wall Street Journal, the perfect birthday party is getting harder to pull off.

Disney and Nickelodeon and Marvel and other similar companies have succeeded in capturing the rapt attention of children.  Rosman quotes an author as writing that, since 1990, the number of television shows aimed at two- to five-year olds has quintupled.  The characters on these shows quickly become adored by near-maniacal throngs of children, who come to desire every possible exposure to Nemo or SpongeBob or Spider-Man.

In most cases, the characters’ creators happily oblige, providing everything from Nemo socks to SpongeBob backpacks.  But the companies have thus far been unwilling to authorize the use of adult-size costumes of the characters, which makes it difficult to grant a five-year-old’s birthday wish to have Dora the Explorer at her party.  Finding Nemo is harder than you think.

The sticking point for owners of the rights in the cartoons is the difficulty of policing and regulating the use of their characters.  Rosman aptly describes this fear: “they don’t want Dora to show up at a party with a cigarette dangling from her mouth.”  This concern is a valid one; any divergence from the character’s TV appearance, personality, interests, or other traits risks confusion, disillusionment, or even revulsion on the part of the adoring children.

Ineffective regulation of a trademark’s use can result in its abandonment.  While it may sound cruel to deprive children of their favorite TV characters on their special day, the risk of losing rights in a character through ineffective policing and abandonment is far too great a risk for companies to please small groups of children at a time.  So, companies instead opt to keep tight grips on their characters, arranging appearances only at more public (and more expensive) places like theme parks, where both the ease of regulation and the level of exposure are higher.