statistics on actual weekly hours worked – typically measured in labour force surveys – give a more accurate impression of how many hours workers really work in a given week, as they include factors such as overtime and absence. However, the national data on average actual weekly working hours are often problematic for purposes of comparison, given differing definitions.

That would seem to be quite right. If you try to look into comparative working hours, you find differing definitions and sometimes wildly differing data. Compare, for example, what the UK Labour Force Survey offers as actual hours worked by full-time employees in Britain for the final quarter of 2007 (Carley's reference period):

with the French Enquête d'Emploi (labour force survey) run by INSEE, that cites comparative numbers based on full-time work by all employed persons (including non-salaried) as 41 hours for France, 43 hours for the UK. There are clearly differing definitions.

So Carley goes on to say that he offers

harmonised Eurostat data for the average number of actual weekly hours of work in the main job of full-time employees, based on its labour force survey for the fourth quarter of 2007. These hours include all working hours, including extra hours, whether paid or not.

Hooray, harmonised data! Let's toddle along to Eurostat working hours data from the Labour Force Survey.

It's not hard to find Carley/EIRO's figures as quoted by the BBC. Average actual hours worked by full-time employees in 2007Q4 are as stated, 41.4 in the UK, 37.7 in France. But, if we look at all employees (full and part-time) we see a different story: 35.1 for France, 35.8 for the UK. This is explained by the fact that part-time workers work shorter hours in the UK: 18.9 (UK) against 22.9 (France), and that part-time workers constitute about 25% of UK employment against 17% for France. So when all salaried employment is counted in (as Jérôme pointed out), there's precious little difference between the two countries...

Even more, if all employment, employees plus non-salaried workers, full and part-time, are counted in, we get (for the same final quarter of 2007, and again from the harmonized Eurostat figures quoted by Carley/EIRO/BBC):

France 36.7 compared to UK 36.2

Er, the lazy frog jumps higher than the gritty brit? Wonders will never cease!

(PS: I know all this has been pointed out before, but it's as well to freshen it up with newer stats!)