Controlling gentrification through desirability

[greenOak 25]

Gentrification / Mansion popup / R$$$ unemployment has been one of the most talked about topics in the SC4 community. As far as I know, the main ways of dealing with this are:

1. Blanket neighborhoods in pollution

2. Zone (light density) no more than two tiles deep

3. Mark R$/R$$ buildings as historical

4. Use the no kickout lower wealth mod (the one by Cori)

5. Use the less abandonment mod (by bones1)

Unfortunately, none of these are that appealing to me. The less abandonment mod is the most appealing but in my experience doesn't help very much in practice. The no kickout mod eliminates any type of gentrification which I think is an interesting mechanic. Marking buildings as historical also shuts off all gentrification and can be very tedious. Zoning no more than two tiles deep only works for low density zones. Using pollution just seems mean and for the most part only works for preserving R$ buildings.

A couple years ago, this thread by Psiman caught my eye - Modding / Recalibrating Land Value. In theory, this would be exactly what I'd want, but unfortunately progress on that seems to have stalled.

The last couple of days I've been messing around with other exemplar properties using Reader, and have gotten some promising results. Lets first examine what exactly the problem is. Consider the city below:

https://drive.google.com/file/d/1QB60_Tv1TDCRYxidMBpVOFTDOCjr7CPO/view?usp=sharing

This city has about 6000 people, and has just been hooked up to a region with large demand for R$, R$$, and R$$$. I have also just put in a school with a basketball court and a small playground. Note there is a dirty industry area that can't be seen in the picture that most sims are currently working at and the pollution is spreading into the top-left part of the neighborhood. Using default maxis settings, I get this after a couple years of simulation:

https://drive.google.com/file/d/1Sxvje13yMTF038yyOolT_uaTtU7FOBai/view?usp=sharing

A single elementary school, basketball court, and small playground is enough to drive desirability high enough that the neighborhood becomes flooded with R$$$ mansions. There is also already dilapidation. Using the no abandonment mod, the situation looks a lot better:

https://drive.google.com/file/d/1uaqvmMcMQrVHDEvRtUMlKov2Dz-Ko7ah/view?usp=sharing

We have increased desirability to the point where R$$ moves in, but not enough to the point where R$$$ moves in. However, you don't need to add much more to get mansions to pop up. The mayors house and a house worship is more than enough. Note that the overlay is from a mod that shows park aura (Cori's Parks Aura)

https://drive.google.com/file/d/1KxJHw_nDBE_ZmmaFusGnZQP_okLtuHOk/view?usp=sharing

Additionally one can simply add a bunch of trees or bus-stops which give a transient aura effect large enough to get over the desirability threshold. 

 

The main problems I see are that:

1. In general it's too easy to raise desirability to the point where R$$ or R$$$ sims move in (governed by exemplar 0x87cd6355 - Desirability Threshold Growth)

2. Transient aura effects make it too easy to temporarily push desirability over the above threshold (governed by exemplar 0x87cd6397 - Transient Aura Effect)

Other exemplars I looked at were:

0x87cd6348 - School Effect
0x87cd6348 - Hospital Effect
0x87cd6341 - Park Effect (on desirability)
0x87cd6354 - Desirability Threshold Decline
0x27812850 - Park Effect (magnitude + radius for specific lots)

 

My goals were basically two-fold:

1. Make it possible to provide education and healthcare to a R$ neighborhood without increasing desirability to the point where R$$ sims move in.

2. Make it difficult to raise desirability to the point where R$$$ sims move in so that R$$$ will grow in very select areas. Basically, this would allow R$$ areas to naturally exist.

 

I made a few changes. First, I greatly reduced the magnitude of the park effect for all parks (and rewards once I get around to it), as well the radius (but not as much as the magnitude). This was coupled by increasing the maximum desirability increase park effect could have (R$: 10 -> 20, R$$: 24 -> 36, R$$$: 30 -> 60). Thus, it is more difficult to get maximum park aura, but the reward for doing so is greater. 

I increased the range of the hospital effect for R$$ (-10 to 10 instead of -8 to 8), and R$$$ (-20 to 20 instead of -10 to 10). In my experience, both hospital and school effect tend to be binary, and thus contribute to desirability by either giving the minimum value (subtracts from desirability) or maximum value (adds to desirability). 

I reduced all transient aura effects by a factor of 4. By default they can range anywhere from -100 to 100, now they range from -25 to 25. 

I increased the desirability threshold growth for R$$ to 100 (default value is 50), and the desirability threshold growth for R$$$ to 160 (default value is 50, it is 120 with the no abandonment mod). Desirability threshold decline for R$$$ was raised from 50 to 100.  

 

Now let's take a look at the results:

https://drive.google.com/file/d/1zZ-Iu_0eUCvSkG2m0Qxw3tZm3dGGgeSP/view?usp=sharing

Even with the school and a hospital, there is only a limited amount of R$$ sims moving in. In fact, once the transient aura has decayed, the area is no longer desirable enough for R$$ to move in. Now I fill in the middle block with 3 large green parks, 1 medium green park, and a few small green parks and open grass areas.

https://drive.google.com/file/d/1hmHGnnmln2v8ZzRQim5UR2Og7GzSXsEn/view?usp=sharing

The neighborhood is mostly R$$, aside from the right-most houses which aren't covered by the school, and the houses to the upper-left which are affected by pollution from an unseen industrial era. R$$$ houses have developed but only in the areas closest to the central parks. 

These seem like big improvements to me. After I'm done fiddling with the park effect of rewards, I'm going to try playing a region from scratch using these settings. I'll report any interesting findings here. I'm also going to mess around with the desirability thresholds for commercial buildings as blocks of CS$$$ buildings next to slums is another thing that's always annoyed me.

[Whte_rbt 1,431]

@greenOak FYI: Your google drive links are all coming up as 'Access Denied'.