Lump of labour fallacy

The assumption that there is a fixed amount of work to go round, so that letting new entrants into the job market will penalise existing workers. It was once used to argue against women joining the workforce and is still used against immigrants. But the fallacy ignores an obvious point; that new workers earn wages and then spend those wages on goods and services produced by other workers. Indeed, the global population has increased enormously over the past century, yet most people have found jobs.