They won't always. You'll always have turn-over - but if it's a major problem for your company it's clearly something you need to work out internally. People, generally, hate switching jobs, especially in an uncertain political climate, especially when expenses are going up - there is a lot of momentum to just stay where you are.

You may lose a few employees to poaching, sure - but the math on the relative cost to hire someone for 100m vs. training a bunch employees and losing a portion of those is pretty strongly in your favor.

A tamper-proof electronic collar with some C4.