[brownbat]

Excellent question! Mostly the research of people like John Ioannidis or Brian Nosek or Megan Head.

http://journals.plos.org/plosbiology/article?id=10.1371/jour...

https://www.google.com/url?sa=t&source=web&rct=j&url=http://...

http://www.npr.org/sections/money/2016/01/15/463237871/episo...