Full employment does not mean that everybody of working age is employed because, in any dynamic economy, some unemployment is unavoidable. For example, there will always be individuals moving in and out of employment as they change from one job to another, and there will always be seasonal, techno¬logical and overseas factors that cause fluctuations in the jobs available in differ¬ent sectors. The real problems arise when there are large numbers of unemployed for long periods of time, as a large pool of unemployed labour represents wasted resources. This is particularly worrying when the unemployed are young — say, between 16 and 25.