I always wonder about #2. Does building more housing reduce house prices in the long term, or does it just encourage more people to move to an area, keeping pri

I always wonder about #2. Does building more housing reduce house prices in the long term, or does it just encourage more people to move to an area, keeping prices the same over time (or possibly increasing them even further as people start having kids)? I know there are studies showing that building generally decreases prices, but there's also the example of traffic and adding lanes to highways.