"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.
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