Taxes and population

By taxing the colonist and native populations you can generate megacredits for building mines, factories, defense outposts, a starbase and starship components.

The populations will become upset with you if the tax rate is too high or if there is over population.  They may become upset if there are too many mines, factories, or defense posts due to environmentalist movements begins within the population.  Over several turns the populations of a planet may become very unhappy.  If they ever become too unhappy they will start a riot or even a civil war.  If this happens they will kill each other and destroy your mines, factories and defense posts. If a riot starts the tax rate will be instantly set to 0% to prevent a civil war.

A high tax rate slows the birth rate.  You can use this factor to prevent over population. Keep in mind that a population with a tax rate of 0 will cause the population to expand at the maximum rate.

A  planet's climate will also affect the maximum population and the birth rate. Temperate warm planets provide the best possible conditions for all lifeforms. Desert and arctic planets are the worst possible conditions for life.  If the population is ever greater than the population that the planet's climate can sustain, the colonists will consume supplies to survive. If the climate is too harsh you may have to make regular freighter runs of supplies to the planet to keep the colonists alive.