I found this poll saying 30% of French citizens doesn't read any books, and close to two-thirds reads less than five a year (I'm guessing the aforementioned 30% is included in that... otherwise it'd be fairly extreme). Another article says that 86% of Argentines reads five books or less per year. For Spain, the best I found was numbers for Catalonian children and young adults (as reported by themselves and/or their parents, so not sure how reliable that is), with 30% saying 3 or less, 35% saying 3 to 6, and 25% more than six. Edit: oh, and apparently 24% of Dutch, Flemings and Surinamese read more than 20 books a year. I'm not sure if that means Dutch-speaking people read a ton more than their French-speaking neighbours, or if it's just a sign of the questionable reliability of these surveys, and the difficulty of comparing polls using differently phrased categories. The detailed survey says about 10% reads zero books a year, an additional 25% reads 1-4 and 46% reads more than 10 - more than 50% of Dutchmen, but only 34% of Flemings. I think we have to conclude these statistics vary widely between countries after all... within one and the same survey, and between two closely related countries, that's a rather huge gap.

I really don't think reading less is the cause for the hardcover thing, though. It's just a matter of what you're used to, is all. I certainly agree with Larry that books in the US are cheaper than here, and I would suspect the size of the market has a lot to do with that - makes for bigger print runs, and hence the editor doesn't have to make as much profit per copy sold. And if even paperbacks are more expensive here than in the US, then the price for hardcovers would be even steeper, so makes sense that hardcovers often aren't even released, then. (And that Germany does have them - the German market is the largest in Europe, after all, what with covering Austria and half of Switzerland in addition to Germany).