Homeland Security and U.S. Immigration Strategies



Yifan Liu,

Date and Time

May 30, 2006 12:00 PM - 1:30 PM


Open to the public.

No RSVP required


Reuben W. Hills Conference Room

FSI Contact

Laura C. Page

Nearly all male adults illegally crossing the US-Mexico border, most of whom are Mexicans, are seeking employment, although a few may be terrorists. We are particularly interested in the impact of immigration strategies on the probability for an OTM (Other than Mexican) terrorist to enter the country, which is based on four models: (a) Discrete Choice Model, (b) Border Apprehension Model, (c) DRO (Detention and Removal Operations) Model, and (d) Illegal Wage Model.

These four models explain the inter-relationship among four key variables -- crossing rate, apprehension probability, removal probability, and illegal wage, which are also affected by other factors, such as detention policy, DRO beds, work site enforcement and legalization policy.

Model (a) introduces a combination of the multinomial-logit model with backward recurrence; model (b) is mainly based on the data we have and the previous research work; model (c) is a 2-class priority queueing analysis with inhomogeneous incoming rate; and model (d) includes some economic theory. Numerical results and discussions are given based on the model parameters existing or estimated from the data provided.

Yifan Liu is currently a CISAC science fellow, and Ph.D. student in the Institute for Computational and Mathematical Engineering at Stanford University. His Ph.D. dissertation, under the supervision of Lawrence Wein at the Graduate school of Business, uses operation research methods to construct mathematical models for homeland security issues, and solve these models both analytically and numerically.