There are probably a lot of variables here, for example when I lived in Edinburgh there was a local company that always had job-openings for Perl programmers. I could have applied for it, but never did because their salary was 50% less than anything else local.

Whenever I hear companies struggle with hiring at least a lot of the time the reason is that there are better jobs available in the same city for more money.

Whenever I've been between jobs I've just googled "Sysadmin $location", and tend to find a new position within 2-4 weeks. But if there are five adverts and two of them have low salaries I ignore them.