I'm trying to understand how projects (for planets) work and how the numbers are generated.
When I first worked with them, they seemed to be a way to stop the darn idle planet problem at the end of the turn. However, I recently decided I wanted to make sure that they worked the way that I thought they did. My assumption was, that they were like the spending wheel in the governor screen. I assumed that when the planet ran out of things to build, the percent of production that went to manufacturing went to the project. For instance, if I had 33% going to manufacturing, it would instead go to research or economics if I used the right project.
It turns out that I was mistaken. When I investigated, I found they did not work the way I thought they did.
1. Research and economic projects did not work the way I thought they did. I first set the project to economic or research. I then set spending to manufacturing to 100% (to see the output to the project made). I then set spending to research or economics to 100% (to figure out the normal rate). What I found was that projects got me less research and economics than what I would have got had I adjusted the spending wheel manually. I was getting rates that might have been 1/2 or even 1/3 of what I could have been getting (it varied depending on where I did it at). Clearly, those projects are not worth using.
2. Approval project. I toyed with them and found that for every 10 point in manufacturing, I got a 10% approval bonus. If I had 10.2 manufacturing, I got 10% approval. If I had 16 manufacturing, I got 10% approval. If I had 19.8 manufacturing, I got 10% approval. If I got 20.2 manufacturing, I got 20% approval. I haven't exhaustively tested these numbers (I don't know if less than 10 points will get me anything), so I'm check to make sure the rate really is that.
3. I don't have any way to measure the effects of population growth, so it doesn't do me much good to test birthing subsidies.
I was hoping that these projects worked well. It saves me the trouble of setting manufacturing to 0. It also makes it so that my planets will automatically upgrade themselves (since projects are only done if there is nothing else to do). However, if there is going to be waste, then it probably isn't worth my time using them.