A Wall? Mike Rappaport

Tyler Cowan addresses whether the US should build a wall:

Mexicans illegals enter the U.S. through two major channels.  Theyrun (or swim) across the border, or they buy illegal papers.  Usuallythe papers cost more than the hiring the crossing guide.  The papersmake for an easier and safer journey, for obvious reasons.  Mexicanwomen, I might add, are more likely to use false papers, given their(their father’s?) greater aversion to the physical strain of four daysin the desert.  If you shut off the desert walks (assume the fence is impregnable, ha!), more Mexicans will use illegal papers. Hispanamerica is coming, like it or not.  Let’s deal with it constructively.

Interesting, but I think a commenter on his site gets the better of him.  She points out that  the question is not merely whether there is an increase in illegal paper immigrants, but the magnitude of it:

A better (and I think less blinkered by the result that you want)argument would have been to point out a wall won’t stop all illegalimmigration from Mexico and that the new steady-state may be hard topredict as the sudden shock to the system will cause a ripple ofeffects.

Giving an example of one ripple, the increased illegal paperbusiness that Tyler correctly forsees would almost definitely becountered by an electronic immigrant database (which has already beenproposed, though for other purposes) that will make the use of illegalpapers for entry significantly more difficult.

Beyond just presenting a credible argument, a better one (thoughprobably not doable in the setting of a quicky blogpost) would’ve beento 1) examine the effectiveness of walls (in terms of percent decreasein illegal immigration), 2) estimate the likely effectiveness and 3)place the effectiveness side by side with the likely cost of the wall(a much easier number) and then ask is if the effect worth the cost. To help sort out the ripple effects, an empirical study of theeffectiveness of walls throughout the last century could be employed(e.g., Israel, Berlin, the soon to be wall on the Saudi Arabia/Iraqborder, various security fences around private and publicinstallations).

Read the whole post and the many comments.