Decadent Lifestyle
Concept · Stellaris 4.5.2
Decadent Lifestyle in the Stellaris encyclopedia: Pops have +20% Happiness, unless there is a Consumer Goods deficit.
Decadent Lifestyle in the game's words
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Pops have +20% 
Happiness, unless there is a Consumer Goods deficit.
… … provide Pop Growth (or Assembly) Speed scaling with their percentage of the 
Colony population. This requires free 
Housing and Amenities, and no Consumer Goods deficit.
We deserve only the best. They must serve, we must rejoice.
Source: common/game_concepts (concept_decadent_lifestyle) and localisation/english, Stellaris Cygnus v4.5.2 (9776).