. True in a closed system, but due to societal values (at the time for instance it was believed that married women shouldn't work, they were being selfish in taking a job that a single woman or man with a family to support desperately needed when they already had a husband to provide for them), age factors (pensioners and schoolchildren), those otherwise outside the active labour force (mainly the independently wealthy but also tramps and addiction victims) and other commitments which preclude free movement of labour (conscription to the armed services for instance) the population does not correlate with the labour force. Nor is Britain practising autarky or juche, she is a global trading nation and goods are being produced for export as well as domestic consumption. So when an economic niche has no one local trained/qualified to fill it or is not remunerative enough for those employed locally to consider switching into it or the young men who might normally have filled it are deployed on military service I think that we can with propriety describe the situation as a labour shortage.There is no such thing as a labor shortage. The demand for labor is created by the demand for goods and services. If you have fewer people, you have less demand for goods and services.