FIrst time I've heard of
The Tinkerbell Effect. But it all make sense. From io9.
The Tinkerbell Effect spans multiple scientific disciplines, including economics, but perhaps its most dramatic demonstration is in psychology - where it literally makes people see things.
There are multiple Tinkerbell Effects, but they all get their name from the scene in the stage play of Peter Pan during which Tinkerbell is dying and the audience is told to clap if they believe in fairies. Perhaps there has been an audience that failed to clap (and I would love to know if the actors prepare for such a thing), but generally they clap, and Tinkerbell springs back to life. If people believe something, it will occur.
In psychology, it just makes people believe that something they believe in will occur. This happens a lot.