And, merit hoarding for regular members is surely less of an issue than for merit sources, and I am pretty sure that in the first round of merit source member assignments, some of those members who were assigned as merit sources, were really stingy regarding their sending out merits, and some of them even publicly stated such.
Right, I'd probably agree with that. If a merit source isn't spending the majority of their spending allocation, it's probably a good time to reconsider them as a merit source, but only really if you think someone else would be able to replace the amount they're sending, and in a somewhat useful way.
I think if we look at it at implementation, users didn't really understand the importance of merit, and there was a lot of experimenting so large amounts were thrown around initially. However, as the standards set by the community sort of came into play, so did the stinginess you talk about. Basically, merit is like bloody gold these days, and you'll find even some very good posts only receiving one merit at a time. theymos did counteract that by increasing merit source allocation though. So, the answer doesn't always have to be new merit sources, but increasing the allocation of the current merit sources. Although, currently I think we're at the sweet spot, since most merit sources are probably only just about spending their allocation every month, and any more would likely be wasted.
Otherwise I agree with your overall assessment Razmirraz that it appears that current merit source members are way more inclined to liberally send smerits as compared to either the first batch of merit source members and perhaps even the second batch.. so it may well have taken a bit more than a couple of years to get each of the incremental improvements in achieving more liberal sending of smerits from merit source members.
There's also the issue of
attrition over time a certain duty might become a little less exciting to certain users, or they might feel they aren't making as big of an impact as they once were. Some will get bored of only sending merit to the same users, time over time, and get frustrated that newer users aren't popping up as often as before. I guess what I'm trying to say is natural variation will take course, and therefore habits will change over time. That either means we need to do something about getting more eyes on the forum, getting new merit sources or increasing the allocations of the current merit sources.