A headcount is the process of counting all personnel during an emergency, like a building evacuation due to fire for example.
The strategy for the headcount procedure will vary from company to company, based on their location (is it a floor in a highrise building or a single isolated building?), the number of people in the company (are they 5 or 5000?).
Because while you might be able to recruit a person new to the job market and underpay them, you won't be able to keep a competitor from hiring them away from you by offering higher wages and benefits. If you are not fair in what you are paying people won't want to work for you.