I am proud of this article that I had a big part in writing, which was now chosen by LessWrong as a “gem” worthy of reposting.
I have not contributed anything new to the concept of acausal trade, but it is the first article I know about the topic: Previously there were nothing but hints in LessWrong comments. This article has been cited a few times. There it is possibly it is still the best article on the topic.
Thanks to Michael Vassar who explained the topic to me in 2012. That understanding inspired me to write the article