Economists at universities in Frankfurt, Arizona and Ontario, who released their joint study on Wednesday, found that "aggregate" hours worked annually were highest in the US and Switzerland.
Europeans across 18 countries studied worked between 16 and 19 percent fewer hours on average than Americans, when looking at the 15-to-64 age group and taking into account those employed, unemployed or partly employed.
The team, comprising university economists Nicola Fuchs-Schündeln, Alexander Bick and Bettina Brüggermann, examined three sets of labor force surveys to extract "new data" suitable for cross-country comparison.
Their examination should open up new avenues for research, they said, especially on vexed questions such as labor supply, productivity, tax incentives, sampling methods, and to what extent factors like staff not using all the holiday available to them could impact upon each nation's estimated yearly average of working hours.
Their sources were the European Labor Force Survey, the US Current Population Survey and Germany's Microcensus.
Total hours 'lower' in Europe
Weeks worked were "uniformly" lower in Europe than in the US, they concluded.
"The mean hours worked per person within each European region are quite similar, ranging from 1,102 hours in southern Europe to 1,144 hours in Scandinavia," the team said.
Individuals in Scandinavia and to some extent western Europe were more likely to be employed than US citizens, the report added.
To arrive at the national averages they looked at the rates of employment within each nation's labor force, hours worked per employed person, including part-time workers, and sourced data from "non-vacation" weeks to avoid distortion.
Employees being entitled to more vacation days each year accounted "uniformly across Europe for between one third to one half of the hours difference to the US," they concluded.
Tough deals for US staff on holiday, sick pay
German newspapers such as the "Frankfurter Rundschau" and "Berliner Zeitung" ran a matching article Wednesday, pointing out that one third of US Americans had no entitlements to sick pay and tended consequently to attend work even when feeling ill.
Furthermore it noted that more than a quarter of US employees did not receive paid vacations. Those who did have entitlements often let their holiday days expire, unused, the article said.
Data sets diverge 'vastly'
The transatlantic research team presented complicated calculations to cope with "vastly different kinds of data sets and methods to construct hours' estimates" supplied by statistical agencies.
They added that the Organization for Economic Cooperation and Development (OECD) was also cautious in drawing oversimplified cross-country comparisons.
According to information on the German government's statistical bureau Destatis, a typical full-time employee worked 41.4 hours per week, but the nation's average dropped to 35.2 hours when part-time employees with their average of 19 hours was included in its equation.