Elaborate this statement?

The most clear instances of compulsory joblessness are those with less work opportunities than jobless specialists in any event, when wages are permitted to change thus regardless of whether all opening were to be filled, a few jobless laborers would in any case remain. That occurs with repeating joblessness, as macroeconomic powers cause microeconomic joblessness, which can boomerang back and intensify those macroeconomic powers.