Telling people via mass media that they should behave better doesn’t have a great track record :-/
I think at least the prevailing view in public health is that it does. This report is a decade old, but was the clearest summary I could find on a quick search. They do emphasise that media campaigns are more likely to be effective when awareness is a major issue and when the desired behaviour change is not that large (both seem true in the case of DMI).
I don’t think the report you link to supports your claim. In particular, while it shows some evidence that mass-media campaigns can raise the awareness of an issue, there is no conclusive evidence that they make anyone actually change their behaviour. And that’s before we look at the cost-effectiveness of the whole thing.
They do give a few examples of changing behaviour. For instance:
However, a controlled trial of a TV advertising campaign in central and northern England provides evidence that mass media campaigns may be able to change behaviour. The campaign was effective in reducing smoking prevalence by about 1.2% over 18 months.
However I agree that it doesn’t have fantastic evidence of that. But most of my impressions of this come from talking to people who work in public health; my understanding is that at least in rich countries, properly targeted public health campaigns are actually very cost-effective. How this carries over to poor countries is another question, but as a baseline I’d at least assume it’s plausible.
They do give a few examples of changing behaviour.
One—which you quoted—and which they offset by the immediately following paragraph which says (emphasis mine):
A study found that the proportion of people who were knowledgeable about the new recommendations increased significantly after the campaign, although it was unclear whether it was TV advertising or other elements of the campaign that made the difference (Hillsdon et al., 2001). However, there was no evidence that the campaign raised levels of physical activity.
There are more examples on the following page (although they are all time series rather than controlled trials, the effect sizes are large enough that it is implausible that they all represent natural background shifts).
I certainly don’t think that all public health campaigns are effective, or that awareness always translates into action. I just thought that your statements sounded surprisingly negative about the possibility of them being cost-effective.
I think at least the prevailing view in public health is that it does. This report is a decade old, but was the clearest summary I could find on a quick search. They do emphasise that media campaigns are more likely to be effective when awareness is a major issue and when the desired behaviour change is not that large (both seem true in the case of DMI).
I don’t think the report you link to supports your claim. In particular, while it shows some evidence that mass-media campaigns can raise the awareness of an issue, there is no conclusive evidence that they make anyone actually change their behaviour. And that’s before we look at the cost-effectiveness of the whole thing.
They do give a few examples of changing behaviour. For instance:
However I agree that it doesn’t have fantastic evidence of that. But most of my impressions of this come from talking to people who work in public health; my understanding is that at least in rich countries, properly targeted public health campaigns are actually very cost-effective. How this carries over to poor countries is another question, but as a baseline I’d at least assume it’s plausible.
One—which you quoted—and which they offset by the immediately following paragraph which says (emphasis mine):
Negative evidence is evidence, too.
There are more examples on the following page (although they are all time series rather than controlled trials, the effect sizes are large enough that it is implausible that they all represent natural background shifts).
I certainly don’t think that all public health campaigns are effective, or that awareness always translates into action. I just thought that your statements sounded surprisingly negative about the possibility of them being cost-effective.