That is from the LifeWay/GuideStone 2018 SBC Compensation Study.
The $77,979 figure is for senior pastors only and the amount includes salary + housing allowance + FRV of parsonage + Social Security equivalent + utilities paid on church owned housing + insurance benefits + retirement contribution. There were 3,536 SBC churches that participated in the survey.
The link allows you to check results by position, church size, church budget, state, etc.
The initial news release noted that compensation hasn’t kept up with inflation but the average is about $2,500 more than the same category for 2016.
And, yeah, I know the average isn’t such a great metric.
Carol Pipes has a good article on Facts & Trends.