No. More cities is better. If you're generating 1000 beakers per turn, an additional city only needs to generate 50 science to break even with the 5% increase, which isn't that hard, just grow it a bit and staff specialists like your other cities. All bpt over 50 is faster science for you. Later if you're generating 2000 beakers per turn you want 100 per city, and even that's not crazy. By going wide you might have some cities that are not pulling their weight but on balance you will still have more science. The 5% penalty is only against shortness - low-population low-output cities, especially puppets - not wideness. Meaning if you are both wide and tall then you will have more science. The penalty-calculated theoretical desirable city output scales with era - a puppet isn't going to kill you much in early game when that puppet's 10 bpt is still 5% of 200 - but then that puppet is more concerning when you're total bpt is 500 - you need to annex and grow that city now. In practice just avoid pre-BNW-style puppet empires generally and you won't have to worry about the ideal city count, more is better. This thread was resurrected from 2011. Those early posts are not referring to BNW at all.