The crude labour force participation rate indicates size of the labour force in proportion to the size of the total population.
The labour force participation rate is computed by taking the total number of persons in the labour force in the numerator and the total population in the denominator and then multiplying the quotient by 100. For example, according to the 1991 census of India:
The male labour force participation rate of 51.55 indicates that India in 1991 there were 51.55 male workers per 100 males. The female labour force participation rate was 22.25 per 100 females the labour force participation for the total population was 37.50 per 100 populations.
These rates, though useful in ascertaining the proportional number of workers in the total population of a particular sex is affected by the age distribution of the population, fact, these crude labour force participation rates suffer from all the weaknesses of any crude rate used in demographic analysis.
Though the total population is taken in the denominator while computing the labour force participation rate, it is obvious that very young persons and very old persons cannot possibly work an therefore, are not exposed to the risk of labour force participation. This labour force participation rate can be refined by taking in the denominator only that population which can work.