TY  - JOUR
AU  - Hanson,Gordon H.
AU  - Spilimbergo,Antonio
TI  - Illegal Immigration, Border Enforcement, and Relative Wages: Evidence from Apprehensions at the U.S.-Mexico Border
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 5592
PY  - 1996
Y2  - May 1996
UR  - http://www.nber.org/papers/w5592
L1  - http://www.nber.org/papers/w5592.pdf
N1  - Author contact info:
Gordon H. Hanson
IR/PS 0519
University of California, San Diego
9500 Gilman Drive
La Jolla, CA  92093-0519
Tel: 858/822-5087
Fax: 858/534-3939
E-Mail: gohanson@ucsd.edu

Antonio Spilimbergo
International Monetary Fund
700 19th Street, N.W.
Washington, DC  20431
E-Mail: aspilimbergo@imf.org
M2  - featured in NBER digest on 1996-09-01
AB  - We examine illegal immigration in the United States from Mexico over the period 1976-1995.  One challenge is that we do not observe the number of individuals that attempt to enter the United States illegally; we only observe the number of individuals apprehended attempting to cross the U.S.-Mexico border illegally.  Based on a simple migration model, we postulate the existence of an apprehensions function, which expresses apprehensions at the border as a function of illegal attempts to cross the border and U.S. border-enforcement effort.  We estimate a reduced-form apprehensions function using monthly data on apprehensions at the U.S.-Mexico border, person hours the U.S. Border Patrol spends policing the border, and wages in the United States and Mexico.  We find that a 10% decrease in the Mexican real wage leads to a 7.5% to 8.8% increase in apprehensions at the border.  Under plausible conditions this is a lower bound for the effect of the Mexican wage on attempted illegal immigration.  It is the purchasing power of U.S. wages in Mexico, not the purchasing power of U.S. wages in the United States, that matters for border apprehensions, suggesting that migrants expect to maintain ties with Mexico.  Border apprehensions are higher in the month following a large devaluation of the peso and higher when the change in the Mexican real wage is negative.  Each additional hour the U.S. Border Patrol spends policing the border yields an additional 0.25 to 0.33 apprehensions.
ER  -