Very interesting!
What are the reasons that in many precincts with strong PSC results (and strong 2017 C's results) the ERC is relatively strong (often in second place) whereas Junts is basically non-existent? Who are these voters? Are they like most of their neighbors when it comes to language, class, family history, etc.?
The explanation may well be more complicated than this, but wouldn't you expect a place that leans left unionist-speaking to also lean left separatist-speaking?
Good point. In the end if you did a principal component analysis on the precinct results you would probably get two main components (left-right and unionist-separatist) and then it would be completely logical for a precinct in the left-unionist quadrant to have ERC in second place (and sometimes ERC and Vox fighting for second place).
Class is probably correlated with the components, too, with the gradient generally going from poor left-unionist to wealthy (or rural) right-separatist, but with a non-linear bent at the end that puts right-unionist areas in Western Barcelona on top.
But I was also trying to immagine the voters behind the numbers and that's why I originally asked the question.