The main cause behind their absence has been named as hectic schedules. Big Bang, Psy, and Sechskies are all due for comebacks in December, and are currently busily wrapping up album productions and preparing for concerts. Attending '2016 MAMA', expected to occur for a total of 3 days, will be too excessive for the top YG artists.
A rep of YG explained, "'MAMA' opened up online voting on December 1, and we don't know if there's the possibility of winning an award yet. However, even if we do get invited, it's been decided that it would be impossible to prepare a performance for the award show."
The rep then emphasized that YG's absence was not caused by any conflict between the label and Mnet, and said, "We hope there won't be any speculations or misunderstandings."
This decision by YG Entertainment only applies to the '2016 MAMA'. You'll still be able to spot YG artists attending other end-of-year award ceremonies!