That is already a record for an entire campaign, with Wigan Athletic's sacking of Malky Mackay this month taking the total to 17 - four more than the previous high of 13 from two years ago.
However, Premier League sackings have dropped from eight to five year-on-year, meaning last season's record total of 12 is unlikely to be surpassed.
The LMA said that the average tenure of a league manager was just 1.57 years, a figure which fell to below a year (0.94) in the Championship.
The Premier League average is 2.27, although that would immediately plummet to 1.34 were Arsene Wenger's 18-year stay at Arsenal to come to an end.
The LMA also said that 15 of the 40 sackings this term were of first-time managers, more than half of whom do not get a second job.
One of those to buck the trend is Chris Powell, who lost his job at Charlton Athletic in March but was the first man given a new one this season when Huddersfield Town sacked Mark Robins just one game into the Championship campaign.
Powell said that the new £5.5 billion domestic Premier League television deal had made the life of a second-tier manager more precarious than ever.
"The majority of football clubs want to get back to the holy grail that is the Premier League," he said. "With the increased revenues from the new TV deal, people are dying to get there, no matter how."
Powell, who was at Charlton for three years, said: "You do need that time, that small four-letter word that you'd love to have in football."
Powell said that managers were fully aware of the LMA's statistics when accepting a new job.
The former England left-back also warned that the figures were of such concern that drastic action may be necessary.
"I feel that there could come a time - and it's been mooted before - where there's going to be a sort of managers' transfer window."
