I don't know about you guys, but i haven't been seeing merits decay after the cycle ends until another week.
first week, i made 1600+ (then FD ed up the rollover, and i got 1890 carried over). next week, i had the full 1890 carryover, earned 1k more. the next week, i had 1945 (or 1k, plus 50% of the first weeks). the same was verified for 2 others in the thread we had.
pretty sure NONE of the models I or anyone else has presented account for the strange numbers seen. FD's merit math is obscure at best, totally ed up at worst.
So the real answer, OP, is that nobody knows for sure.