Then you have the altogether different question of how "excluded" the unemployed are in both systems:

• in terms of living standards (certainly better in Europe)
  
• in terms of personal well-being and social standing (not sure)
  
• in terms of being able to find another job (likely better in the US, where long term unemployment does seem to be much less)

Who is unhappier - someone who has to struggle with one - or more - low paying job(s) to make ends meet, or someone who has no job. The perceived malaise in continental Europe suggests that it is the latter, but it's hard to know if that's what the actual workers/unemployed think or if the "common wisdom" of the times about the respective systems that has taken hold and spread around?

In the long run, we're all dead. John Maynard Keynes

No they don't. They exclude everyone in institutions and the military, and they don't correct for passive job seekers as far as I can see. The OECD numbers certainly don't. The OECD uses the ILO agreed methodology. The ILO themselves charge for reports so I can't get at their info as easily as the OECD.

The agreed definition of unemployed is as above, and it's a matter of national policy of exactly what "actively sought work" means, as the document linked to discusses. The ILO guidelines are subject to interpretation in several places. Incidentially, I don't think the ILO have numbers - they use the numbers compiled by the national labour surveys with various corrections based on data available in the surveys.

The ILO requirements don't even tie down the two-week vs. one-week availability issue. I'm reasonably certain that no-one corrects for these things because no-one knows how to.