Just because a worker can handle one occupation, it is not certain that he or she can handle all occupations. Therefore, a worker needs to be able to limit his job search.
But the existence of the middle class is based on the right to be able to limit their job search in times of unemployment. So this also needs to be able to limit his job search in times of recession, layoffs and unemployment to avoid jumping between the job as an economist at Handelsbanken and restaurant assistant at McDonalds.