Throughout history, walls have been built primarily for the purpose of defense (The Great Wall of China), politics (Berlin), religious separation (Northern Ireland), ethnic divide (Cyprus), or some nasty combination of all four (Israel). But rarely are walls built purely to rebuff wage invaders.

Illegal immigration is an economic issue, thus the rules of supply and demand apply. If the demand for illegal workers is cut, wages for illegals will fall, and the supply of immigrants will fall as well. Right now it is a challenge for employers to verify the legal status of some workers (although, our policy of turning a blind eye doesn’t help).

The immigration bill currently in Congress addresses this by adding $1.6 billion for a computerized system to verify the eligibility of applicants for lawful employment. Once this is in place, fines could be increased for employers caught employing illegal immigrants. Voila, demand for illegal immigrants falls and so would the number tempted to cross an open border.

But the immigration bill directs twice as much money to the Department of Homeland Security. DHS is being authorized to spend $3.3 billion on border defense that consists of 370 miles of fencing and 500 miles of vehicle barriers that will only cover 47% of our border with Mexico. Construction of one foot of the fencing alone will cost $568.

Israel has spent billions of dollars on walls, trenches, even a proposed sunken highway. Meanwhile, smugglers between the Sinai Peninsula and Gaza spent just $76 per foot to tunnel underneath. We should count ourselves lucky to only have impoverished day workers trying to cross our border (I discount the terrorism threat - terrorists could more easily cross our 5,500 mile border to the north).

By employing a historically military tactic to a primarily economic issue, we will spend ourselves into a hole.  At least there will plenty of illegal immigrants to help us dig it.

Sources: Sunken road: Cornell University, The Current; U.S. Mexico Border Fence: Congressional Budget Office estimate; Isareai Wall of Separation: Palestinian Environmental NGOs Network; Fourth generation of Berlin Wall: Berlin Wall Online; Smuggling Tunnels: Defense Update; Vinyl Picket Fence: Hoover Fence, Co.

Notes: According to Berlin Wall Online a 3.957 foot wide segment of the Berlin Wall cost 359 East German Marks in 1975. Because this was not a freely traded currency, historical exchange rates are hard to come by. However, as a note of comparison, Berlin Wall Online mentions that a loaf of bread cost 1.04 East German Marks at the time. Thus the store of value in a segment of the wall is equivalent to 345 loaves of bread. In 2006 in the price of a loaf of bread in the U.S. averaged $1.30, so each 4 foot segment of the Berlin Wall was valued at $448.75. It’s not perfect, but you get the idea.