> but being in a course means you are not counted as "looking"/"available" for a while

Are there enough people to whom that distinction applies to be more than statistical noise relative to the other regional variations that would have an impact?

Seems like a minor nit to pick in the grand scheme of things.

Austria is regularly criticized for doing this through such measures and others (pushing people into early retirement as well).

Here is a thing in English that seems to come for free if you give them bogus personal data: https://www.agenda-austria.at/en/publication/austria-the-lan...

A longer German blurb about this study is here: https://www.agenda-austria.at/oesterreich-das-land-der-verst...

They claim 250,000 hidden unemployed for 220,000 "official" unemployed for Q1 2013, i.e., the official figures would be off by a factor of more than 2. But they don't say how many of those hidden unemployed are in training courses. Maybe the full study does say, I can't be bothered.

Thanks, surprised it's that significant of an impact.

Yes it is, since those countries allow people to claim unemployment while not looking for work (via a rather silly rigmarole way of doing so, but still). At the sharp end, there are fewer people in that country who want a job (whether because they'll lose their unemployment if they don't get one or otherwise) and can't get it.

All that is true for the unemployment rate itself. It just means that the unemployment rate is not a useful proxy for a country's economic health, as it is often taken to be.