How do I increase demand in a city, population of around 45,000?

My city is close to perfect but I can't seem to get any demand -- it's negative in all categories!

It has a population of 45,000, and all but one bar of mayor rating filled up. EQ (education) is nearly 200 everywhere, all the opinion polls are full (except environment and traffic, which are ~3/4). Average salary ~70,000. Water is supplied to all parts of the city, and the city has full school/library/college/museum/police/fire/hospital coverage (well-funded).

I have no dirty or manufacturing industry, but some high-tech (~3000 jobs); the rest of my city is commercial. I installed a small subway, which is used about half as much as the roads, and I have a LOT of city beautification ($1000/month+ worth of parks, etc.)

I'm pulling in a little over $800 a month with taxes at about 9% for medium/high residential and 7% for commercial/high-tech. There's a few "no jobs" indicators in the residential sectors, but no demand for commerce/industry.

I tried a bunch of different things (without saving), but nothing seems effective. I added an airport and a landmark (Bank of America tower), which temporarily sparked some commercial, but very little. I tried lowering taxes to zero, but even that did nothing except bankrupt me in 6 months.

I'm trying to make a self-sufficient city, so there's no connected cities, but if I must add them I will. I want to explore other options first, though. Thanks!

Solution 1:

Cities have kind of a maximum independently-sustainable size in SC4. It sounds like you did a pretty awesome job for a single location. Once you've reached critical mass however, neighbor cities become vital. I'm sure you know that having neighbor cities with populations that need jobs will foster job demand in your main city. Having neighbor cities with jobs will foster residential needs in your main city.

Solution 2:

Here's a few different things that could help.

Zone Density

Are you zoning higher density zones? Without those, your city will definitely be capped at a lower population. This is pretty basic, so I doubt this is your problem if you've reached 45,000, but worth mentioning.

Cap Relief

Each population type will only grow up to a certain population cap. This starts very low, but most everything you add to the city raises these caps for the types of population that like what you've added. That's what you saw by adding an airport and then a landmark, the commercial population cap was raised. When a population is over its cap, the demand is forced down. When a population is under its cap, demand grows normally.

One of the main tools Sim City 4 gives to deal with population caps is the building rewards. If you find all of your demand is negative, go check to make sure you've placed all the reward buildings you can. The people love the reward buildings, and they give great cap relief. Often a city is simply waiting for a new stadium to be built before they'll grow any further. (I have a small hunch that waiting for a stadium might actually be the problem at 45,000)

Tax Cuts/Raises

Do not cut taxes. Changes in demand due to taxes have a large temporary piece, then a long term small part. After a couple months the people get used to the new tax rate and demand gets quickly back to what it was. Unless you raise taxes significantly, changing the tax rate is not an efficient way to affect demand.

No Jobs

A lack of a job causes a sim to leave the city, meaning lower demand. Often times you have the job they need in the city, but they simply can't get to it commuting every day. The answer to this is of course better transportation. Keeping the transportation system running smoothly means that far more buildings are used to their capacity, sims have jobs, and thus money to spend, and thus demand for other types, which is eventually self fulfilling.

Single City

Prariewolf's answer is spot on. At some point, playing with limited space, you'll reach a point where you can't grow the current city any more without building a neighbor city. That neighbor city provides and fulfills demand through any connection you can make, and both city grow larger than either could have alone. In short, you can't maximize one city alone. In Sim City 4, this was designed to be a big effect, such that you WANTED to build neighbors before trying to maximize one city.