Google has never been shy about the fact that it automatically puts results from some of its own services at the top of search results pages if these help answer a users’ query faster. If you type in an address, a map from Google Maps might give you the instant answer you need.

But how often does Google do this, does it always result in superior results, and what effect does it have on companies that offer rival services? Ben Edelman, an assistant professor at Harvard Business School, has tested what he calls “hard-coding” by the search engine – that is, where it overrides the normal algorithmic results to put a Google answer first – and concludes the practice is now common. Read more