There is a fair amount of research out there on the effects of copyright and patents. From my casual observation, it feels murky as far as causal relationships

There is a fair amount of research out there on the effects of copyright and patents. From my casual observation, it feels murky as far as causal relationships go, but then it is not a field I actively study. The effects are also not independent of the actual implementation of IP rights - it can help or hinder and there might be some optimal setup. I certainly wouldn't dismiss that there could be a copyright implementation that is net helpful for fostering creativity and innovation.