"Unemployment" covers the most important collection of variables in economic policies. The unemployment rate can influence the outcome of elections or cause and trigger riots. This makes the interpretation and finally the definition of "unemployment" a political issue. This should be kept in mind when starting cross-country comparisons.
Consequently the definition of "unemployment" may vary by source. But supranational sources, e.g. Eurostat, the statistical office of the European Union, provide harmonised statistics for their members. Whenever possible make sure to retrieve unemployment statistics from a single source only.
Definitions by source:
Unemployment – Eurostat, Statistical Office of the European Union
"Unemployed persons are those who, during the reference week:
(a) had no employment, and
(b) were available to start work within the next two weeks, and
(c) had actively sought employment at some time during the previous four weeks.
In addition, unemployed persons include those who had no employment and had already found a job to start later. "
Unemployment – International Labour Organization (ILO)
The unemployed comprise all persons above a specified age who during the reference period were:
without work, that is, were not in paid employment or self employment during the reference period;
currently available for work, that is, were available for paid employment or self-employment during the reference period; and
seeking work, that is, had taken specific steps in a specified recent period to seek paid employment or self-employment.
"The specific steps may include registration at a public or private employment exchange; application to employers; checking at worksites, farms, factory gates, market or other assembly places; placing or answering newspaper advertisements; seeking assistance of friends or relatives; looking for land, building, machinery or equipment to establish own enterprise; arranging for financial resources; applying for permits and licences, etc."