In March 2018, Google ran a global test of zero-results pages. These were search result pages that contained no organic links and only one knowledge card. Dr. Pete Meyers of Moz chats with host Brian Childs about the initial analysis of the Zero-Results test, why he believes it was conducted, and how businesses should think about the implications. His article on the subject is here: https://moz.com/blog/zero-result-serps