In the last couple of posts, I've outlined why it is that the sermon-writing process is different for UU ministers and why it is that we are not in the pulpit every Sunday. And, of course, this has ramifications. And the impact of this is different for bi-vocational (part-time) ministers. It's important to look at this, since bi-vocational ministry is getting a lot of interest these days because of the increasing struggle of churches to afford full-time ministry, particularly in the changing religious landscape with fewer people in younger generations interested in traditional church. The bi-vocational trend may need to look different in our UU churches than it does in other denominations.
Generally in our movement, it seems that half-time ministers preach twice a month for ten months of the year, or a total of 20 sermons. They don't really get extra Sundays off for denominational leave; those are just scheduled into the half time that they're not working -- even though, of course, denominational work and continuing education is, indeed work. Note that two half-time ministries would equal more than one full-time ministry -- a minister with two half-time ministries would have no off Sundays, and no Sundays free for continuing education, chapter meetings, and General and District/Regional Assemblies, unless that half-time minister was preaching at two churches on the same weeks at different times.
Now think about what percentage of a minister's time is devoted to preparing for and leading worship. With a full-time minister, it might be as much as 20 hours a week on those weeks the minister is preaching, or 60 hours in a four-Sunday month. If that minister is working, conservatively, 50 hours a week for those 4 weeks of the month (pretend this month is February that we're talking about), then that's 60/200 hours, or 30% of their time devoted to worship.
With a half-time minister, suppose that minister is working, again conservatively, 25 hours a week for four weeks of the month, and preaching twice using 40 hours devoted to worship preparation. That's 40/100 or 40% of their time. So the bi-vocational minister will need a greater percentage of their time for worship preparation.
The problem is, what do you decrease and do less than half of? Not pastoral care. Trust me, you can't just refuse to answer every-other pastoral need. You're doing 100% of that, not the 50% that half-time ministry would suggest. So that's going to take a double percentage. Now you need to cut something else even more. Perhaps you only respond to half of the social justice issues in your community? The major area to cut is committee work and administration, but administration is a hidden work of the minister to begin with, that congregations don't think you're spending much of your time on.
Basically, as every half-time minister knows, there's no such thing as half-time ministry.
This becomes even more complicated for 3/4-time ministries, particularly when increasing from half-time ministries. A church increasing from half time with 20 Sundays wants naturally to move to 30 Sundays for 3/4 time, which is virtually full-time ministry from a preaching standpoint. With preaching and worship being a large percentage of the job.
If, again, you start with assuming a 50-hour week, 3/4 time of a 4-week month would be 150 hours. Three sermons at 20 hours each would be 60/150, or 40% again. It's a slightly better struggle than half-time ministry, because you're still doing 100% of pastoral care and 100% of everything else that you can't really do less at, but now you're getting paid for 75% of it. So it's closer to workable. But the big problem is when you try to go to full-time ministry without any substantial increase in the number of Sundays, so what the congregation is getting for paying you 25% more is basically just the good feeling of knowing they're paying you fairly for the work you've already been doing, but they aren't going to see much more result for it. I suspect, as a result, sadly, the 3/4-to-full jump is the hardest to make.
Ultimately, I want to say that bi-vocational ministry is harder in our tradition because the worship preparation time is harder in our tradition, and it's the most visible and desired part of ministry, and part-time ministers really are seldom given the amount of time they need to devote to it, without just working more and more hours for part-time pay. This is one reason why you find ministers less willing, in our tradition, to consider part-time ministry.