**Response to @paulg:**

Here's the article that graph came from. It offers no explanation for the pattern.

economist.com/international/… (https://www.economist.com/international/2023/04/03/was-your-degree-really-worth-it)

https://nitter.moomoo.me/pic/card_img%2F1650995584206098433%2FYd_kFbk6%3Fformat%3Djpg%26name%3D800x419

https://nitter.moomoo.me/paulg/status/1655264737234497537#m