Yes, the amount of drugs seized and where comes from Customs. Just like the example I gave would get its data directly from the FBI crime statistics. Then they acknowledge my very same criticism that this data is not directly connected with overall smuggling methods but assure us that it is indicative of how drugs are smuggled:Lol uncited experts? This is data straight from Customs.
"While those numbers deal only with drugs that are caught, border experts say the data accurately reflect the way drug cartels successfully smuggle narcotics into the country."
Yes, uncited 'experts' say that the data is correlative and present nothing to show that it is. Indeed, the article continues on pointing out the myriad of ways said data is NOT indicative of how drugs are smuggled over the boarder but they do so in order to establish that a wall would not be effective.
I notice you were unable to point out how your explanation of the data differs at all from the counter example given. Because you cant. Because you know you are using the exact same failed logic.