How many people standing say, every 100 feet, are required to cover 2000 miles 24 hours a day in some of the most dangerous inhospitable desert on earth? Let's just assume conditions are rosy and leave that part out for simplicity sake. 1 mile = 5280 feet, so 52.8 people per mile.

2000 miles x 52.8 = 105,600 agents, per 8 hour shift. 105,600 x 3 shifts = 316,800 agents per 24 hours.

Covering 7 days a week, 24 hours a day, with 168 hours in a week, you will need 4.2 x 316,800 to man the wall = 1,330,560 people. Considering that 24 hour positions need approximately 1.5 full time equivalents to cover vacations, holidays, and sick leave, you're now up to a force of 1,995,840.

Roughly 2 million people to do the job.

At $50,000 per year salary/benefits total package, that's an annual payroll of $100 Billion dollars. Not counting vehicles or equipment.

If by some miracle, you do the job with 1/4 the calculated number of people, that's still 500,000 agents, requiring $25 Billion, EVERY YEAR, without even calculating equipment and facility costs, because they are going to need to potty, eat, and drink while on the job.

Are you sure that "MORE PEOPLE" is the answer? I'm not trying to be a dick. It's just that the people argument is way more expensive EVERY YEAR than the entire cost of a physical barrier.