The rate of unemployment in the United States is obtained from a telephone survey of households in which the proportion of the labor force actively seeking and unable to find employment is determined. (In other countries, statistics are based on those registered with the unemployment office; thus international comparison may be inaccurate). Unemployment rates may be distorted by underemployment (part time work), discouraged workers and underground economy.
Some countries measure the unemployment rate using the proportion of those who filed for unemployment benefits. The survey (of those seeking employment) method used in the United States appears to be better because some people may file for unemployment while working for an employer "off the books".