Check out the following screenshot:
Why do so many of my cities have a science output of zero?
Why does Ayr, a city with 358 Commerce, have only 40 Science, when Mount Isa, a city with 306 Commerce, has 210 Science? (Ayr and Mount Isa have the same building inventory, so their total building maintenance is identical.)
Why does Cairns, a city with 8 Commerce, have the same Science output as Alice Springs, a city with 194 Commerce?
For that matter, why does Cairns have only 8 Commerce? It's a size 20 city, and within its city radius are 7 Forest tiles (10 Commerce each) and 4 Beach tiles (10 Commerce each). Similarly, Ultima, which is listed as having only 3 Commerce, has 6 Forest tiles and 6 Beach tiles within its city radius.
Is this a bug? Or is it some inexplicable part of the game design?