Gross Income

The Gross Income of a colony is the modified by the effects of wealth improvements, such as the  or the. The sum of the of every colony is the  of the civilization.

Generation
The most bonuses to come from Improvements, including the, , , , , ,   and many trade resources.

Other bonus sources include:
 * Certain starbase modules
 * Assigning a leader to "Wealth", which increases
 * The citizen promotion in
 * The technologies, , and in
 * Certain cabinet members in
 * Certain mercenary ships in
 * Certain planet types
 * Certain colonization events
 * An anomaly in the Precursor Worlds DLC
 * The Economical trait