Luxuries help draw keep citizens happy and attract them away from other cities, but to a lesser degree than durable goods. As an example of how the satisfaction level of a luxury good works, pretend that you have a city of 80k people with 1 music and 1 rug:
  • the rug serves 80k (the whole city) contributing 20% to satisfaction
  • the music serves only 40k (half the city) contributing 10% to satisfaction
  • the city has a 30% luxury satisfaction rating
People tend to stock up on goods and the satisfaction rating can only change by 5% every year, so the actual luxury satisfaction rating in a city usually won't reflect the luxuries available on the market that year.
Booksweight: 2 decay: 2%
Jewelryweight: 1 decay: 1%
Rugweight: 30 decay: 4%
Wineweight: 40 decay: 2%
Theatreweight: 30 decay: 18%
Musicweight: 10 decay: 15%