Tourism Income

Tourism Income provides wealth every based the amount of tourism, an abstraction of the cultural accomplishments of a civilization. In, the amount of is based on the number of tiles in the zone of control, with tiles connected to the capital being worth twice as much. The amount is normalized by the map scale (see below). Receiving requires the  technology.

Bonuses to
The most effective way to increase is to invest in. However, it is possible to specifically increase by constructing achievement improvements, such as $$, $$,, , , and.

A few other bonuses to are available, including:
 * The United Planets Tourism Board resolution
 * The Tourism Minister in the Plutocratic government in
 * Certain planet types
 * The resource
 * The Popular trait
 * The technology, available to Devout factions
 * Certain colonization events and a galactic event

Normalization by map scale
Increasing the map scale attenuates, according to this curve: