I am working on a quantitative analysis of SO. I am particularly interested in the causal relationships in the system.
Examples to causal questions that I can think of are:
Does daily limit on reputation points cause users to contribute to the website constantly?
Does putting up a bounty for a question cause that question to get more answers?
Does being able to edit answers/questions cause high quality answers/questions?
Depending on the causal question, I am analyzing the data in SO to verify the causal effect in the system.
If there is any causal question you have about the system that you would like to be verified with a data analysis. Please let me know. I will be happy to share my results with the community.