A short post in between, so I can share two thoughts:
1. it is now possible to post reactions to my blog posts. Because I'm new to blogging, the settings were not very inviting previously. Now, you can react very easily. Please do if you feel like it. I believe in progress by debate.
2. I am not a specialist in the concept of causality myself, but I love Judea Pearl's blog on the topic of causal relationships, counterfactuals and the role of covariates in the social sciences. He recently posted some great links, new ideas and video's. Go and read it if you have a spare hour.