Mattels’ Barbie has had many careers since she came on the scene in 1959: fashion model, astronaut, teacher. Maybe these have prepared her for her swimsuit debut on Sports Illustrated Swimsuit Edition 50th anniversary cover this week. Or maybe not.

In the last decade Barbie sales have dropped dramatically, down over 25% and younger models (ahem, American Girl dolls) are overtaking her on sales. Is Barbie now a doll for adults… and how did this happen? We take a deep dive into the history and the economics of the Barbie Girl world.