>In traditional industries like manufacturing you don’t hire 500 factory workers unless you have a production line that needs them. You don’t over-hire based on a guess.

This is interesting, in my experience its seemed to be the opposite.

In manufacturing, its must easier to come up with a specific number of employees you need for a given project or contract.

If the contract is expected to sign you may hire early to get ahead of it.

If the contract falls through, or an existing contract is cancelled, you know exactly how many people you need to cut to balance labor with your current commitments.