1. Public fears of vaccines are vulnerable to exaggeration as a result of various influences, emotional, psychological, social, and political.
2. Fears of public fear of vaccines are vulnerable to exaggeration, too, as a result of comparable influences.
3. High-profile information campaigns aimed at combating public fear of vaccines are likely to arouse some level of that very type of fear. As Cass Sunstein has observed in summarizing the empirical literature on this effect, “discussions of low-probability risks tend to heighten public concern, even if those discussions consist largely of reassurance.”
4. Accordingly, an informed and properly motivated risk communicator would proceed deliberately and cautiously. In particular, because efforts to quiet public fears about vaccines will predictably create some level of exactly that fear, such a communicator will not engage in a high-profile, sustained campaign to “reassure” the general public that vaccines are safe without reason to believe that there is a meaningful level of concern about vaccine risks in the public generally.
5. Not all risk communicators will be informed and properly motivated. Some communicators are likely to be uninformed, either of the facts about the level of public fear or of the general dynamics of public risk perception, including the potentially perverse effects of trying to “reassure” the public. Others will not be properly motivated: they will respond to incentives (e.g., to gain attention and approval; to profit from fears of people who understandably fear there will be a decline in public vaccination rates) to exaggerate the level of public fear of vaccines.
6. Accordingly, it makes sense to be alert both to potential sources of misinformation about vaccine risk and to potential sources of misinformation about the level of public perceptions of the risk of vaccines. Being alert, at a minimum, consists in insisting that those who are making significant contributions to public discussion are being strictly factual about both sorts of risks.
Here's a point that occurs to me in reflecting on some of the throughtful responses to yesterday's post.
I have been conflating "movement" with "public opinion." When I see "growing anti-vaccine movement," I am reading this to suggest that there is a sizable segment of the general population -- as opposed to a social outlier fringe, akin to people who believe "contrails" are part of a secret government operation to spray toxins on vulnerable populations or manipulate the weather.
Again, I know there are indeed such people (from reading Mnookin's excellent book, e.g.). I agree they are a menace. Perhaps they are growing in number, too, but I don't think they are any less of a concern if their size is merely holding constant.
The reason I equate “growing movement” with “growing public opinion,” though, is that the media and other reports that I’m addressing do.
They write of a "growing crisis of public confidence,” a “growing wave of public resentment and fear,” an “epidemic of fear” etc. that have “result[ed] in outbreaks as herd immunity breaks down,” etc. This suggests a much more fundamental state of anxiety, a much more widespread level of nonvaccination, and a much higher resulting incidence of childhood disease than actually exists in the US today. If I'm right to belive that, then this strikes me as an ill-considered “risk communication” strategy.
[Latest post -- I hope last on this topic for time being -- reflecting how, w/ benefit of commentators' help & more reading & thinking, I now would sort out what strikes me as real & important from what strikes me as really unfortunate.]