Measurement unemployment rate

There are also different ways national statistical agencies measure unemployment. These differences may limit the validity of international comparisons of unemployment data."  To some degree these differences remain despite national statistical agencies increasingly adopting the definition of unemployment by the International Labour Organization. To facilitate international comparisons, some organizations, such as the OECD, Eurostat, and International Labor Comparisons Program, adjust data on unemployment for comparability across countries.

Though many people care about the number of unemployed individuals, economists typically focus on the unemployment rate. This corrects for the normal increase in the number of people employed due to increases in population and increases in the labour force relative to the population. The unemployment rate is expressed as a percentage, and is calculated as follows:

As defined by the International Labour Organization, "unemployed workers" are those who are currently not working but are willing and able to work for pay, currently available to work, and have actively searched for work. Individuals who are actively seeking job placement must make the effort to: be in contact with an employer, have job interviews, contact job placement agencies, send out resumes, submit applications, respond to advertisements, or some other means of active job searching within the prior four weeks. Simply looking at advertisements and not responding will not count as actively seeking job placement. Since not all unemployment may be "open" and counted by government agencies, official statistics on unemployment may not be accurate.

The ILO describes 4 different methods to calculate the unemployment rate:

• Labour Force Sample Surveys are the most preferred method of unemployment rate calculation since they give the most comprehensive results and enables calculation of unemployment by different group categories such as race and gender. This method is the most internationally comparable.
• Official Estimates are determined by a combination of information from one or more of the other three methods. The use of this method has been declining in favor of Labour Surveys.
• Social Insurance Statistics such as unemployment benefits, are computed base on the number of persons insured representing the total labour force and the number of persons who are insured that are collecting benefits. This method has been heavily criticized due to the expiration of benefits before the person finds work.
• Employment Office Statistics are the least effective being that they only include a monthly tally of unemployed persons who enter employment offices. This method also includes unemployed who are not unemployed per the ILO definition.

The primary measure of unemployment, U3, allows for comparisons between countries. Unemployment differs from country to country and across different time periods. For example, during the 1990s and 2000s, the United States had lower unemployment levels than many countries in the European Union, which had significant internal variation, with countries like the UK and Denmark outperforming Italy and France. However, large economic events such as the Great Depression can lead to similar unemployment rates across the globe.