More disguised unemployment? Without the generous European benefits, of course.
I should be able to find this myself, but I have not been successful.
Being inactive isn't necessarily a bad thing.
Here's the real point: comparing unemployment rates across economies is at best difficult, at worst wilful bullshit.
It is intriguing, though, to note that some countries generally cited as examples of economic "success" have above-average numbers of people inactive for reasons of sickness and disability, while countries currently cited as basket cases (France and Germany yet again) have far fewer.
Since it's the OECD, I imagine they're pretty much comparing apples to apples, but, as you say, there are countries with benefit systems and countries without.
Or vaguely round fruit with other vaguely round fruit, depending on national definitions of fruit.
Oh no, wait, it's a vegetable... But damn useful when you have statistics about round fruity stuff... In the long run, we're all dead. John Maynard Keynes