Thalassicus
Bytes and Nibblers
I forgot to specifically point out here it's policy rate that's important (I explain in more depth in the linked thread). The game's tooltip says cities increase cost, which is true but potentially misleading. When I started Civ 5 I thought each city slows policy generation by 30%, but each city also adds to income, so it affects policy rate in a more complicated way.
The change to Representation affects policy rate by 1-5% per city, depending on empire size. You can experiment with the numbers without a calculator with the spreadsheet I use. On the "Policy Cost per City" sheet, "Lib, Rep, Monuments" row, the "Expense" value can be changed from 20% to 10% to see the difference between vanilla and mod (respectively). Most empires vary between 5 and 20 cities.
The change to Representation affects policy rate by 1-5% per city, depending on empire size. You can experiment with the numbers without a calculator with the spreadsheet I use. On the "Policy Cost per City" sheet, "Lib, Rep, Monuments" row, the "Expense" value can be changed from 20% to 10% to see the difference between vanilla and mod (respectively). Most empires vary between 5 and 20 cities.