Does this mean I can build a city with a couple of power genorators and 50 hotels and a 2nd city on the same planet filled with flats and the hotels will make money as the flats provide the people to fill the jobs in the other city? so the planet overall willhave a good ER rate regardless that the ER's for each city are on oppisite ends of the scale?
ER is based on each city - so to get the best income you would have to design each city to have an ER of as near as possible to 1.5. As for hotels there are a limit to how many you can have per city to get the best income. However if oyu have one city with a deficit of hotels, then you have have more in another city, as its based roughly on the limit, the number of terrain squares etc.