Open Access Heatmap
Number of Open Access Journals per Country
1. To make this OA journal heatmap more informative, it should be compared with the heatmap of the number of subscription journals from each of these countries.
2, Then (to help the eye and brain) a heatmap of the ratio of OA to nonOA journals.
3. That will give an idea of the OA journal situation worldwide (i.e., Gold OA) (though of course it will not be controlled for journal quality or age: the spam journals will be in there too).
4. And if the interest is in an OA heatmap rather than just Gold OA heatmap, it will need to be accompanied by a heatmap of Green OA self-archiving -- first, perhaps, the very approximate one using Google Scholar, for all free online articles.
5. And then 5 controlled for free online articles per publication year
6. Then a WoS or SCOPUS heatmap for total articles output per year
7. Then the ratio of 5 to 6.
8. Then separating Green articles from Gold articles and controlling for publication year, country size, etc.
Lots going on in OA, of which the heatmap of OA journals gives only a minute glimpse...
For a bit more -- likewise only partial glimpses, and already dated, Google the work of (a) Gargouri et al, (b) Bjork et al, (c) Eric Archambault and (d) Lee Giles.
thanks a lot for your comment. Of course all the things you mention would enrich the heatmap. But please remember I wrote above that the data I used is "trivial" - the heatmap was just a by-product as I was preparing a presentation I'll give next week. I never intended to write a scientific article or to conduct a scientific study - even though I know quite well how to design such a study. The heatmap was just meant to be a spotlight and nothing more. Anyone that wants to go deeper is free to gather, analyze and process data on Open Access output or to pay someone else (perhaps me) to do this work.