About a year ago, the Food and Drug Administration rolled out nine new cigarette warnings, the first packaging update in 25 years. The images would be significantly more graphic, as you can see above, than what we have now.

The new labels were meant to hit cigarette boxes next month, but don't hold your breath. A federal appeals court for the District of Columbia ruled today that these labels are unconstitutional. The reason: There is not enough evidence that these labels will actually reduce smoking rates to justify infringing on tobacco companies' First Amendment right to free speech.

Here's the relevant passage from the opinion of Judge Janice Rogers Brown, courtesy of the Incidental Economist.

First Amendment requires the government not only to state a substantial interest justifying a regulation on commercial speech, but also to show that its regulation directly advances that goal. FDA failed to present any data — much less the substantial evidence required under the APA — showing that enacting their proposed graphic warnings will accomplish the agency’s stated objective of reducing smoking rates. The Rule thus cannot pass muster.

I did a quick search through the academic literature and there do indeed appear to be numerous studies making the connection between graphic cigarette labels and higher rates of smoking cessation. One Canadian study found that a fifth of adult smokers smoked less after the country rolled out new labels.

The court does acknowledge the large body of knowledge making this link. It says, however, that isn't good enough, that this correlation isn't necessarily a causal relationship. The FDA, Judge Brown writes, "offers no evidence showing that such warnings have directly caused a material decrease in smoking rates." And that explains why these new tobacco labels won't hit shelves anytime soon.