http://www.bloodyelbow.com/2016/8/23/12512178/why-do-boxers-make-more-than-mma-fighters
"For boxing, the combined total amount paid from the 1,320 boxing purses was $228,291,452 with an individual purse average of $172,948. This is skewed more than a little by the enormous payouts Floyd Mayweather (who's reported purses were $100 million and $32 million for his two bouts in 2015) and Manny Pacquiao (who's reported purse was $25 million for his match against Mayweather) received. If you remove their three reported purses from last year (which totaled $157 million) then the combined total for the other 1,317 boxing purses was $71,291,452 which averages out to $54,132.
A more telling statistic than the
mean average for what most boxers earn is the
median average. The median average in 2015 for a boxer in our three states was $3,250.
For mixed martial arts the combined total of the 826 purses was $17,936,216 for a mean average of $21,714 per purse. The median average for MMA fighters was even lower than that of boxers, a meager $1,250."
"While it is readily apparent that most athletes from both sports make very little, with the
mode being only $1,000, it appears as if MMA fighters on average are worse off than their boxing counterparts. Of the 1,320 boxing purses we looked at, 299 (or 23%) of them were for $1,000 or less, while of the 826 MMA fighter purses 400 (48%) were for $1,000 or less. Even though MMA fighters payouts made up only 38% of the total collected they were 57% of all prizefighters that were paid $1,000 or less on a bout.
The reverse was mostly true as well, with a much higher number of boxers occupying the very top of the pay ladder. Of the top 100 purses, those making $116,000 or more, 68 were paid to boxers. Of the 19 biggest purses, all were paid to boxers. The highest reported MMA purse was Anderson Silva and his $800,000 from UFC 183, which was tied with three boxers for 20th place on our list of highest paid purse."