Statistics on the hours worked have been produced for many years in basically all countries in the world. The type and range of these statistics, however, including the coverage of workers as well as the reference periods used, differ between countries depending to a large extent on the measurement methodology used. Establishment surveys mainly produce statistics on “paid hours of work” for a subset of employees and sometimes on “overtime” paid at regular or higher hourly rates and “absence from work” resulting in reductions of pay. Household surveys generally produce statistics for the whole target population on “hours actually worked” and “hours usually worked” for a reference week. In contrast with statistics on hours worked, few (mainly developed) countries produce statistics on working time arrangements or on annual hours worked. Despite the need for such statistics, national statistical offices seldom measure or make estimates for these concepts perhaps because there is little international guidance or consensus on how they are to be defined and measured or estimated.
The heterogeneity in the quantity and quality of national statistics on working time seriously hampers international comparisons and is reflected in ILO publications. The Yearbook of Labour Statistics, for example, publishes national series only on average weekly “hours actually worked” by sex, major industry groups and by division in “manufacturing”. But some countries provide annual averages, either taking into account paid leave, public holidays and other types of irregular absence from work. Others provide simple averages of weekly observations, while still others provide statistics only for a particular reference week. For some countries the statistics refer to “hours paid for” and sometimes even to “normal hours of work”. Monthly or quarterly statistics on average weekly hours actually worked published in the Bulletin of Labour Statistics have the same limitations. The October Inquiry publishes statistics on “normal hours of work” per week and on “hours actually worked” (as well as statistics on wage rates and earnings) for selected detailed occupation groups in selected industry groups. In both cases the statistics actually provided may be for concepts and/or reference periods which are different than those requested.
National statistics on working time arrangements as a whole are not published by the ILO but the Key Indicators of the Labour Market publishes national statistics on part-time employment and annual hours worked for a limited number of countries, provided mainly by the OECD and other international organisations.