Tax
From the Galactic Civilizations Wiki
Tax is the fundamental source of financial income in Galactic Civilizations II. The amount of tax revenue is largely determined by how large your population is and how high your tax rate is set. Increasing the tax rate will increase your tax revenue at the expense of decreasing your approval rating on your planets. Tax revenue can also be affected by Racial bonuses, Planetary improvements, government type, your political party, amount of money in the treasury and game version ("Dark Avatar" gives 40% less money than "Dread Lords"). The income from a planet is given by the formula:
constant * sqrt(population_in_billions) * tax_rate * (1 + (sum from buildings on planet)) * (1 + (sum from racial bonuses/maluses) )
Constant seems to be:
- - 34.5 in Dread Lords
- - 28.5 in Dark Avatar before ver. 1.6
- - 24.0 in Dark Avatar after ver. 1.6, up to current 1.8
- - 20.0 in DA and for planets over 25B pop
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- Notes
- See discussion tab for a formula explanation.
- There seems to be a small penality to tax revenue (up to ~4%) for low approval (below about 50%)
A rough guide to tax levels and their effects on approval rating. Please note the penality to approval is not linear, but "jumps" at each 10th number. Often the best tax percentage is just below it (e.g. 39%, 59%, 79%)
| Tax Rate (%) | Approval (-%) |
| 100 | 398 |
| 90 | 347 |
| 80 | 192 |
| 70 | 163 |
| 60 | 90 |
| 50 | 68 |
| 40 | 48 |
| 33 | 36 |
| 25 | 27 |
| 15 | 16 |
| 10 | 10 |
| 5 | 5 |
| 0 | 0 |
