> If I, as an employer, train you for 6 months, then you leave at month 7 for a higher salary (which you can demand cause you have more training/experience), I lose out. So I have no incentive to train you.

Pay higher than others and employees won’t leave you.

Make delayed payments part of compensation, so employees get the money only if they stay long enough.

Don’t hire employees who change jobs too often.

There are many ways to keep employees from leaving without damaging their careers.