Fair point , thank you for the feedback. As I wrote, I did not detect causation (except for a couple of examples in which the null hypothesis of Granger causality test was rejected). The aim of the analysis was to find relationships between data from Hacker News and Stack Overflow without verification of other data sources , which could influence both websites.
Nor did I say I had found causation neither did write that I had not. I specifically stated that I tested the hypothesis of Granger causality which does not mean causality. Even if the main question of the article was causality, I could not answer it (and I stated this in the text).
Nevertheless, I agree that I should have probably been more careful with the term "causality" so thank you once again for pointing this out.
Nor did I say I had found causation neither did write that I had not. I specifically stated that I tested the hypothesis of Granger causality which does not mean causality. Even if the main question of the article was causality, I could not answer it (and I stated this in the text).
Nevertheless, I agree that I should have probably been more careful with the term "causality" so thank you once again for pointing this out.