Slogging in that overtime might not be all that productive after all.

This is not a novel idea. Last year a YouGov poll showed that working just seven hours a day is the best for productivity levels – despite the fact that the average work day for a Briton is over eight and a half hours.

Expert Market analysed GDP data from the Organisation for Economic Cooperation and Development (OECD) and found that of the 10 countries with the highest GDP, seven of those (Luxembourg, Norway, Switzerland, Netherlands, Germany, Denmark, and Sweden) also make the top 10 list for the shortest working hours.

The top 10 list of productive countries (GDP divided by hours worked) is below:

1. Luxembourg

1643 average annual hours with £45.71 hourly productivity.

2. Norway

1427 average annual hours with £36.36 hourly productivity.

3. Australia

1664.2 average annual hours with £29.81 hourly productivity.

4. Switzerland

1568.2 average annual hours with £28.35 hourly productivity.

5. Netherlands

1425 average annual hours with £28.35 hourly productivity.

6. Germany

1371 average annual hours with £25.95 hourly productivity.

7. Denmark

1436 average annual hours with £24.14 hourly productivity.

8. United States

1789 average annual hours with £23.66 hourly productivity.

9. Ireland

1821.26 average annual hours with £23.12 hourly productivity.

10. Sweden

1609 average annual hours with £22.58 hourly productivity.

16. United Kingdom

1677 average annual hours with £18.64 hourly productivity.

The UK does not make the top ten cut, and slides in at 16th with 1677 average annual hours and £18.64 hourly productivity.

The statistics don’t appear to be too bad, but when compared to Luxembourg’s productivity, which yields £45.71 per hour, the disparity between the two countries becomes large indeed.

According to the Happy Planet Index, Luxembourg ranks 16th globally for life expectancy and well-being, and it is the 6th most equal country on the Index, with low levels of inequality.

Norway is second for well being, and Australia is 12th.