All things (not very carefully) considered

Another off-topic entry to add to the CrazyStats category. Today’s NPR’s “All Things Considered” included a report called “States Fret at Easing of Border Security Plan” which talked about “Operation Jump Start”, so described:

“For about a year, National Guard troops have been rotating in and out of outposts along the [US-Mexico] border. Soldiers stayed visible under blue tents right on the border to deter illegal crossers while scanning the landscape, reporting anyone who did cross.”

It then goes on:

“The deterrent worked. The number of crossers apprehended by the Border Patrol since last October is down by about one-third, while drug seizures are up.”

The implication seems to be that would-be illegal immigrants were deterred by the presence of the troops and that drug traffickers were not deterred but were more often caught thanks to the help of the troops (who presumably either directly caught drug carriers or freed up Border Patrol resources to go after them). Success! But what if the result had been the exact opposite? More crossers apprehended and fewer drug seizures. Couldn’t that just as easily be interpreted to mean that the troops helped in catching more crossers while providing reinforcements that deterred drug traffickers? When opposite results can be interpreted to both mean success the test is suspicious.