The pair concepts of employment and unemployment are so basic to national economies that any rise in employment rate - which means a drop in unemployment - is reckoned as an indicator to the national development. Moreover, the unemployment rate is an indicator for appraising the economic conditions of the country. To quarterly and annually estimate the labor force indicators in Iran, the labor force survey is conducted on a seasonal basis across the nation by using sample rotation. As the survey is over, the outcomes are compared with those of the previous rounds in order to observe thepossible changes in indicators over seasons at the national, urban, rural and provincial levels. The survey was first conducted in 2005 and since then has regularly been taken in the middle month of every season. Another survey titled Household Employment and Unemployment CharacteristicsSurvey (HEUCS) would be implemented before L.F.S. The HEUCS was first taken in 1994 and repeated in the years 1997 to 2000 once a year from October 23 to November 22. From 2001 to 2003, it used to be taken on a seasonal basis, middle month of every season, while in 2004 it was onlyexecuted from April 21 to May 21 and October 23 to November 22. To improve the HEUCS quality and its conformance with the international concepts, particularly those of the ILO, the survey plan wasrevised into the current Labor Force Survey.

The rotational nature of the survey requires drawing on a basic sample– a sample out of which subsamples might be taken to be used in different rounds of a certain survey or in different surveys. The basic sample of the Labor Force Survey for the years 2005-2008 was taken from the 2002 National Establishments Census frame. Following preparation of the basic sample, officials managed to prepare the list of households lied in the fall 2004 basic sample clusters in order to be able to select the sample households based on the rotation pattern chosen for different rounds of the survey. The new basic sample was designed based on the listing information of the Population and Housing Census 2006 as of the year 2009.

Definitions and concepts
Economically active population
All people aged 10 or over ( a specified minimum age) who according to the definition of work have been taking part in production of goods or services (employed ) or have been able to take part in production of goods or services( unemployed) during the calendar week preceding the survey week ( reference week ) are considered as economically active population.

 Employed

All people aged 10 or over who according to the definition of work have worked for at least one hour 1during the reference week or have temporarily left their job for one reason or another, are reckoned as employed. The employed are divided into two major groups of wage/salary earners and the selfemployed.
Being temporarily absent from the job within the reference week, while having a formal attachment to the job by the wage/salary earners and continuation of the business by the selfemployed, is considered employment. The following people are also considered employed due to their
critical role in the national economic activity.
 Persons who, without receiving any remuneration, work for a member of their household that is a relative (unpaid family workers).
 Trainees who perform an activity in relation to the activity of the workshop during the training period. In other words, they directly contribute to the production of goods or services and their activity is considered “work”.
 Students who have worked during the reference week, according to the definition of work  All people who are serving as permanent and temporary cadre in the armed forces (armed forces, cadre personnel, soldiers, commissioned officers, non-commissioned officers of the military forces and the police).
Unemployed The unemployed are all people aged 10 or over who: 1. have no job during the reference week ( not engaged in a wage/salary job or
self-employment,)
2. are available to work during the reference week or the following week ( available for a wage/salary job or self-employment,)
3. have been seeking job during the reference week and the preceding three weeks ( have taken specific steps to seek paid employment or self-employment).

All people who because of expecting to start a job in near future or return to their former job have not been seeking a job - had no job but have been available to work - are also considered unemployed.

The underemployed are all employed people who have been present in or temporarily absent from the workplace and have worked less than 44 hours   during the reference week due to economic reasons

such as work recession, not finding a job with more hours, or non-work season, but have been willing and ready to do more work.

The ratio of the active population (employed & unemployed) 10 years of age or over (15 years of age or over) to the working age population 10 years of age or over (15 years of age or over) multiplied by 100.

The ratio of the unemployed population to the active population (employed & unemployed) multiplied by 100.

The ratio of the unemployed population aged 15 -24 (15-29 years of age) to the economically active population at age 15-24 (15-29) multiplied by 100.