….in order to generate higher pay rates. It’s an economic truth. If there are too few of something the price goes up. More demand for that widget than there are widgets to satisfy the demand will make them more expensive.
In recruiting it takes more than just scarcity. Try finding a Diesel Mechanic when you need one, or good Manufacturing Technicians with PLC programming. They are hard to find and there are more needs for them than there are qualified candidates to fill them.
However, their impact to the bottom line is only so much, so no matter how scarce they are, there is a cap to how much the pay will go up.