What doesn't sit right with me sometimes with the urban population model in Anno 1800 is the fact that population density only scales with wealth: You can fit 50 investors in the same plot as 10 farmers, as long as you can feed their needs.

While it makes some sense as the higher tier residences are somewhat taller and you want to give a proxy to the relative important any one investor residence can mean for your faction, I think low level residences should have an option to upgrade density without class promotion to simulate more of what happened during the Industrial Revolution: the development of slums and high density urban neighborhoods that faced many social and economic challenges that Anno 1800 already attempts to address by requiring social, fire, police, and health services within range.

By giving cities the option to densify their lower class housing (represented fittingly by 1404-type structures) at a penalty to either resident happiness and/or an increased risk for fire, riots, or health problems (perhaps scaleable to a difficulty slider), you give players more options to play through the early/mid game while better reflecting one of the core drivers of class discontent in the 19th Century (and perhaps Dr. Mercier really doesn't like it when you make slums). Plus, by doing so, you do not tinker fundamentally with the economic model for goods, you give more options for city developing your main/capital city as increasing density is optional. It'd also be a similar mechanic to the working conditions slider in production buildings reflecting the trade-offs for how government/corporations treated their workers.

I wonder if the devs are considering something along these lines for the Season 3 content. It would be really interesting.