i've read and replied in several threads about economy in DA - how to maximize money, population, etc.
in the game i've got going now i tried a new method. i put two farms on every planet (except my homeworld, which only got 1), but held on researching the last farm tech. this resulted in the population on every planet being 18 billion, just below the 20b cap where morale plumits. one VRC on each planet, plus 5 morale mining bases, all the morale-boosting trade goods, the krynn's 50% morale boost plus an extra 20% i bought, and the morale boost from playing neutral, and i'm taking them at 79% with an approval of over 80%. if i were at home, i'd post more concrete stats.
this is late-game level development. i've got all the terraforming techs, and only 3 of 51 colonies are below PQ 10. planets of 10 or higher get:
1 starport
4 industrial sectors
1 quantum reactor
2 farms (second to highest level)
1 VRC
1 counter-espionage center
extra tiles are either stock markets or NLCs. my few PQ 8 and 9 planets are sans 1 farm and/or 1 industrial sector.
if i were playing a smaller game and were willing to handle the micro-management, i'd disable the governor upgrading on all my planets, research the last farming tech, and upgrade only 1 farm per planet (resulting in populations of 19b, or 13b for the signle-farm colonies). but when you've got 51 planets and aren't playing for an MV score, it just ain't worth it.
cheers,
nik