All Construction

is the base level of construction at a Colony. Both and  are functions of.

Generation
is largely determined by direct bonuses and the at the colony.

Direct bonuses
Improvements are the most important direct source of.

Other direct sources include:
 * Certain Planet types
 * Certain Colonization events
 * Certain Starbase modules
 * The and  technologies
 * The Productive race trait
 * The Slavemaster citizen
 * In, certain Governments, Galactic events and Crisis events
 * In the Precursor Worlds DLC, a specific type of Anomaly
 * In, specific Mercenary ships

Usage
Drives both and  through linear functions.