Structural unemployment occurs when there is a mismatch between the skills and qualifications of workers and the requirements of available jobs.

It results when there is a change in the structure of an industry or economy, often due to technological advancements, which make certain skills obsolete.

To explain why changes in labour-saving technology are likely to lead to structural unemployment, consider this: When labour-saving technology is introduced in a rapidly growing economy, it often leads to changes in the nature of work and the skills required for certain jobs. 

As a result, some jobs may become obsolete or less in demand, leading to unemployment for workers who do not possess the necessary skills to adapt to the new technological advancements.