I would take “openness”, as typed in an Economist article, to mean something like “[a country/government that] does not snuff out opinions contrary to that of the government, sometimes by disappearing, sending to concentration camps, and/or murdering contrarians”. Or something like that.

Also, I wish people would stop doing such mental gymnastics just to complain - your comment is effectively attempting to amplify the shortcomings of the study that are pointed out in the article you are quoting by then quoting them and adding slightly snarky commentary. Why? The author does a fine job framing what the study actually accomplishes, in their opinion, and then assessing its utility.

On that same note, The Economist article is a commentary on the study and not written by the authors of the actual study. So when The Economist says the results are “interesting” that is not Education First (the company behind the study) claiming their own results are interesting... it is an audience member doing so. Please be accurate if you are going to nitpick so aggressively.

The fact is the article does provide interesting commentary on the outcome of a vast and interesting survey while clearly acknowledging the interesting issues with the data.