Farms Versus Economic Improvement
a second look
http://spreadsheets.google.com/pub?key=pRRxnGooNfKdnLi6yoSgmEwI've lost the thread I saw this in, and I'm tired, so I apologize in advance.
But I caught a thread in which a comment was made about economic items being a far better return on value than farms, since you have to quadruple your population to double the tax base, and the more I mulled it over the more a little voice in the back of my mind started mumbling "No, logarithmic curves don't work quite like that."
So I did the math out in a spreadsheet on Google docs (Yeah, I'm sure this could be better proven using logarithmic math. I'm tired - {G}), and no, the math really *doesn't* work out that way, at least not for quite a bit.
The formatting doesn't work out terribly well - basically I set underline for everything at 20population and bold face at 'breakpoints' for farms - ie, for a +3 farm, starting at 8 the 'break points' for the return on the investment are at pop=11, 14, 17, 20, with the 20 point underlined, where the percentage is the (tax base at pop 11) /(tax base at pop 8) - everything but the last column is calculated as marginal returns, i.e. the return on the 'last' farm (so the second farm is t (tax base at pop 17)/(tax base at pop 11)).
Anyway, Obviously the trade offs vary quite a bit depending on the economic buildings you have and the farms you have, but if you have lousy economic building, you should *definitely* consider the benefits of farms - the first +3 farm on a yor planet give a marginal return of 17%, the second just over twelve percent. I'm not sure (this game has been off and on for several week) but my recollection is that I had to trade to find a 12% econ building, so using the Yor Tech tree I should *definitely* go for the influence bonuses of two +3 farms before I build econ buildings.
By the same token a single +5 to +7 farm is *much* better than the equivalent return on a stock market - at +7, you get a return of not quite 37%, and even the marginal return on a second +6 farm in almost 20%, with a 58% total for the two farms.
Unless I'm missing something fundamental (and I may well be), until you have stock markets, farms are a much better investment, and they may be a better investment up to pop20 than even a stock market.
Jonnan