Remember the RAND study that found that crime increased in areas after medical marijuana dispensaries were shut down? RAND made no causality claims, only correlation, yet the results enraged certain political entities, most notably the L.A. city attorney’s office.
After a lot of pressure, RAND retracted the study. In their news release, they said that the reason they voluntarily retracted it was that they “determined the crime data used in the analysis are insufficient to answer the questions targeted by the study.”
They did not find contradictory information, or any reason to necessarily doubt the findings, but rather decided that the amount of data was insufficient to make the conclusions solely based on that data. They claimed they intended to redo the study with more data, but we’ve heard nothing since.
What’s interesting, of course (though not at all surprising) is the way the retraction has been seen by some as a kind of proof that the findings were false – that, in fact, the closing of dispensaries were not followed by an increase in crime.
That has resurfaced with Scientific American’s article Doh! Top Science Journal Retractions of 2011
#5: Los Angeles marijuana dispensaries lead to drop in crime.
Keep smoking. The RAND Corporation retracted its own report in October after realizing its sloppy data collection.
The tone is annoying, and “sloppy” is a possible overstatement, but the retraction is news, so I have no issue with that.
But it doesn’t stop there. Nick Schou at OC Weekly pens a particularly ignorant column: Rand Study On Medical Pot Among Year’s Worst, Scientific American Says (Notice how it magically escalated from “top five retractions” to “among year’s worst”?) which is then positively linked to by the drug czar’s office.
Keith Humphreys goes even further and claims that the retraction means that the finding that “Closing medical marijuana dispensaries increases crime” was “inaccurate” and “false.”
Humphreys bizarrely accuses others of believing that “a retraction is the ultimate confirmation that a studyâ€™s results are true” while at the same time ignoring the fact that he has used it as the ultimate confirmation that a study’s results are false.
The retraction of a study means absolutely nothing regarding the truth or falsity of the conclusion, only that the study has now been made irrelevant to that discussion.