Possible Causes
Structural unemployment is caused by a mismatch between jobs offered by employers and potential workers. This may pertain to geographical location, skills, and many other factors. For example, in the late 1990s there was a tech bubble, creating demand for computer specialists. In 2000-2001 this bubble collapsed. A housing bubble soon formed, creating demand for real estate workers, and many computer workers had to retrain to find employment.
The causes of structural unemployment can happen because of automation in the work place (e.g. need for higher and higher computer skills), rigidities in the labor market, such as high costs of training or in the case of US de-industrialization as manufacturing jobs are continuously lost to off-shoring.
Some economists posit that the minimum wage is in part to blame for structural unemployment. They assert that because the federally imposed minimum wage is higher than some individuals' marginal revenue product in any given job, that those individuals remain unemployed because employers legally cannot pay them what they are "worth." Others believe that in such cases (for example, when a person is mentally retarded or suffers a debilitating physical condition) it is the responsibility of the state to provide for the citizen in question. When a minimum wage does not exist, more people may be employed, but they may be underemployed and thus unable to fully provide for themselves.
Read more about this topic: Structural Unemployment