Tuesday, July 13, 2010

Sanitary habits and externalities

Last year I was at a meeting at the NIH campus and covered a sneeze with my upper arm. I was surprised when someone commented that they saw very few people do that.  I was very surprised that this would be true on the main campus of the National Institutes of Health.

Of course, we wouldn't expect people elsewhere to be any better.  A study from New Zealand highlighted in an article in the Baltimore Sun notes how few people made any attempt to cover a a sneeze or cough and how many of those who bothered to try actually did so with a bare hand.

Why would an economist be interested?  Both failing to cover a sneeze or cough and covering a sneeze or cough with a bare hand lead to externalities.  Different types of externalities but externalties nevertheless.

An uncovered sneeze or cough exposes others to the airborne viruses. A person who covers a sneeze or cough with a bare hand unfortunately does not keep the viruses to himself or herself but can spread them to doorknobs and other things touched.

The unfortunate thing from an economic point of view is that there is no easy way to provide alternative incentives--except perhaps social stigmatism.  However, if most people are doing this then it is not clear where the stigma would come from.

Perhaps the best we can hope for is better education about the risks and some way of internalizing the risks--at least to one's own family--and then a spillover from behavior toward one's own family to behavior to others.

If anyone could think of creative incentives that could be used in a cost-effective way to change this behavior, I'd be interested.


  1. There are other ways besides economics to provide incentives. We could just start beating people senseless when they don't cover their coughs and sneezes. That is what sometimes happened in the US during the 1918 flu pandemic. Similar accounts of violence occurred during the plague outbreak in Europe in the 14th century. Unfortunately, in the case of plague, ignorance about the vector and reservoir led to badly targeted violence(even in the case of pneumonic plague which probably was in fact spread by coughing and sneezing). Instead of killing rats, which might have actually helped, antisemitism became all the rage with terrible, unspeakable consequences.

    As the risk and consequences of an infectious disease become more widespread and the externalities associated with the disease become more apparent, moral sentiments appear to generate behaviors that more closely align individual and social welfare (e.g., inflicting immediate pain on people who don't cover coughs and sneezes in public). Violence prevention is yet one more reason why public health infectious disease prevention and management is to be preferred to laissez-faire disease management by a highly fragmented clinical health care sector. One also hopes that nowadays moral sentiments would also prevail in preventing irrational, immoral scapegoating of groups when causal links are unknown, not well understood, or ignored because of commitment to anti-science beliefs or prejudice.

  2. While I was in Japan in the summer of last year, and on the entrance of the metro a two young ladies were there distributing small packs of tissues with pictograms on the outer PE pack,
    I can't understand Japanese but I figured out the message,
    In metro and alike crowded place, a reminder for healthy habits like sneezing in a tissue, is of value indeed,
    but if we need to set priorities maybe we have to fight another more dangerous tendency, which is attending office or school while still sick, we have to study the cost effectiveness of being generous with flu sick leaves rather than trying to control millions sneezing,
    We can evidence the priority we select by counting those cases which are secondary for a colleague at work case and those cases resulting from sneezing without covering,
    Nadia Younis

  3. Omniyat Al HajeriJuly 17, 2010 at 12:30 PM

    it is very difficult to change behaviours, i do believe that health education is essential factor here, many would not even think of the problems that they are causing by a sneeze...it is even more difficult to see the problem when somebody covers his mouth with his bare hand... to them they did cover the cough or sneeze, many are not even considering the facts, proper education plus frequest reminders especially with signs that are easily read where ever possible in the crowded area plus media involvement may help show the majority where the problem is.

  4. Great comments from Maxine--the key is to find enough people who are willing to impose on others to actually pull off any type of social sanctioning.

    Nadia makes a good point about awareness of when is the right time to stay home rather than placing others at risk. Certainly within the JHU community there was a big push for people to stay home if they ha flu-like symptoms last year. How many people took heed? Hard to tell. I know of one sign in a men's room on which someone wrote that they would not follow the suggestions. Whether that was written simply out of frustration or actually reflected the opinion of someone associated with a school of public health is difficult to say.

    Omniyat also makes a good point about placing reminders in crowded public areas.

  5. Having a toddler (and, thus, spending more time around other young children), I find that educating & being educated by the next generation is an important key to primary care & prevention. Children, when they've been instructed on proper behaviors/procedures, are not shy about passing on these messages (even to strangers), and they are learning and role-modeling behaviors that adults are having to unlearn. I know the things that my son & my nieces are learning get extended to the rest of our family as we do our best to reinforce what they've learned. I find many adults are more focused on their children's health than their own, so there are many opportunities to address larger family health issues through childhood education.