Researchers at the RAND Corporation believe they have found four promising methods to estimate the number of illegal immigrants who enter the United States, according to a paper released last week.
Researchers at the RAND Corporation believe they have found four promising methods to estimate the number of illegal immigrants who enter the United States, according to a paper released last week (.pdf).
Presently, the researchers argue, the Department of Homeland Security (DHS) has no reliable way to accurately estimate how many illegal aliens cross U.S. borders between ports of entry. This inability to accurately estimate the total number of illegal alien crossings means DHS has no way of knowing how effective it has been in countering illegal immigration and what strategies are the most cost-effective.
"Fundamental to the question of border control effectiveness is the proportion of illicit border crossings that are prevented either through deterrence or apprehension," write RAND researchers Andrew R. Morral, Henry H. Willis, and Peter Brownell. "Estimating these proportions requires knowing the total flow of... border crossings, but compelling methods for producing such estimates do not yet exist."
According to the report, current government statistics—such as the number of illegal migrants caught or miles of border under "effective control"—used to determine DHS's ability to control the border are imprecise and thus "unreliable management tools."
For instance, the report notes that DHS's Customs and Border Protection (CPA) can spin apprehension numbers either way.
Citing a 2009 Government Accountability Office report, the researchers highlight that in regions where CBP had higher apprehensions, the agency said it was due to improved operations. Yet in areas where the CBP experienced decreases in apprehensions, the agency explained that improved technologies and more border agents provided a deterrent effect. (CBP officials from the El Paso sector made this exact argument to me when I interviewed them for my article, "Bordering on Danger ," the December 2010 cover story.) Either way apprehensions are analyzed, CBP achieved its mission.
"Clearly," the report explains, "a measure that reflects successful performance whether it rises or falls has limited value as a management tool."
Instead, the researchers offer four approaches that have the potential to provide more precise estimates.
- Capture-Recapture Methods
- Stratified Sampling
- Respondent-Driven Sampling Surveys
- Synthetic Modeling
While these approaches are more sophisticated, it doesn't necessarily mean they're up to the job either.
"Successfully implementing each of these approaches will require methodological development and analysis to identify barriers or constraints to using the approach, the cost of data collection, and the amount of error that can be expected in the resulting estimates," they conclude.
Because the researchers see measuring illegal border crossings as such a "rich challenge," they recommend that DHS offer competitive grant funding to increase the scientific community's interest in solving the problem.
♦ Photo by ThreadedThoughts/Flickr