Lump of Labour Fallacy

In economics, the lump of labour fallacy (or lump of jobs fallacy) is the contention that the amount of work available to labourers is fixed. It is considered a fallacy by most economists, who hold that the amount of work is not static. Another way to describe the fallacy is that it treats the demand for labour as an exogenous variable, when it is not. It may also be called the fallacy of labour scarcity, or the zero-sum fallacy, from its ties to the zero-sum game.

Historically, the term "lump of labour" originated to rebut the idea that reducing the number of hours that employees are allowed to labour during the working day would lead to a reduction in unemployment. The term has also been used to describe the commonly held beliefs that increasing labour productivity and immigration cause unemployment. Whereas some argue that immigrants displace domestic workers, others believe this to be a fallacy, arguing that such a view relies on a belief that the number of jobs in the economy is fixed, whereas in reality immigration increases the size of the economy, thus creating more jobs.

As a fallacy, the lump of labour often takes the form of a false premise. In rhetoric it is usually a hidden premise, which makes the conclusion of one's argument a non sequitur. That means that the lump of labour is usually either a subtype of a false premise fallacy, a non-sequitur fallacy, or both.