I thought I knew all about wealth but I'm missing something. In my latest game I started tracking wealth a bit to know where to move my metsuke to (early game as Shimazu so I was acquiring richer provinces and some of my poorish starters were making jumps from buildings). At first it was all okay. But then I noticed that Satsuma was declining in town wealth, even though it was constantly showing a +growth at the end of each turn. Argh...

So I went back and checked (a bit) through some saves and some provinces were semi-regularly dropping about 20-30 koku in wealth; even though they were showing growth. Obviously there is one or more factors I was missing.

Candidates: keeping my provinces at 0 happiness (but why sometimes drop and sometimes not?); having non-clan religion in province (once again why sometimes and sometims not dropping?); or something else I haven't thought of.

Any answers or do I really have to reload 20 saves and try to figure it out?