Hi,
I'm a fan of the game brought to life by 
Spoiler alert, it isn't. I've start playing it a little more serious in December where I develop different strategies on it and discover everyday something new to it as every little tweaking has an influence on the global scale of it.
In theory, if I wanted big ROI, I would need to snipe big income cards like the restaurant and fill them with luxury homes. That would give at least 300% ROI if the cards are snipped at the right time.
But as in real life, there are some other factors to take in account. There can be a big influx of population due to the high popularity which will cause the unemployment to rise, adding costs to the city.
There is crime that robs the ROI and there can appear also criminals in the city, which will burn the money.
A lot of variables, but there is one that busts the income the most, like in real life, the taxes.
At the moment the taxes close in to 70% and was set by 
It is not communism, as there taxes would be futile as everything is owned by the state. This is pure socialism where the productive population needs to pay out the unproductive one.
The winners on this cities would be the population generating ones as the population cards can be sold to almost the same price as before. Bringing kids in the world can bring in money.
In the discord people are outraged of not having their 300%/year anymore. Where this number is a huge compared to 99,(9)% of the available investment methods on the market. Now we are at 100% due to the taxes and people complain because of it, even if this again is a very good return. There are manufacturing industries running with 1-3% a year and this industries bring you food on the table. Imagine the markup on this ones.
Like said, this is a perfect simulation of socialism. We have this also in Western Europe and I don't see people complaining that much as in the discord of this game. Taxes have a very big impact on the business side and most companies can't develop and grow due to this. Also taxes affect the employees, where for example a top earner in Sweden pays 60%, something like in DCity and people accept it. I don't know why, but I have to pay also 42% in Germany and don't complain but try to find the loops to avoid this taxes, like in the game where are some good opportunities to keep a high ROI. This I will not disclose today, as I let the taxes eat the inflation for a while and enjoy the destruction caused by the DCity socialism.
If you play DCity, how do you feel about the taxes? How do you feel about the taxes where you live? What affects you more and where do you act more? And how is your view on socialism?