A very common ailment in Korean summers and falls is pinkeye (conjunctivitis), and the problem had been getting much worse in the past two years. My Korean co-author tells me, however, that the H1N1 virus has created a positive externality in Korea.
These days, people are encouraged to wash their hands more frequently, and they appear to be doing it. That has sharply reduced cases of pinkeye. On net, I imagine that the economic costs of the swine-flu epidemic exceed the costs of the pinkeye outbreak. Nonetheless, it’s always nice to note the silver lining in an otherwise dark cloud. I wonder how many other examples there are of positive externalities arising out of negative shocks.
(Hat tip: J.L.)

–#6 Arvin:
I don’t think you mean nuclear research. Virtually all the WWII rocketry research was finalized by 1939 in the powers who fought the war.
But I don’t mean to distract from the discussion, I’m just saying that the world might have gone in some amazing directions if WWII had been avoided.
Not really an externality but Americans are saving more due to current economic crises. Now that might sound good but we need spending at this time. So actually a negative externality out of something positive.
It would be particularly interesting from a Machiavellian point of view if the positive externality were greater than the cost.
#5: As an English teacher in Korea, I can tell you why: Kids don’t wash their hands. At least before the swine flu. Now, there’s a sign showing the SIX-STEP PROCESS (in the local language, of course) showing everyone old and young how to Wash Your Hands. A number of us in the Korean blogging community have laughed at the about-face, although we tend to appreciate the causality of things: a flu threatens, and everyone suddenly believes that being clean will keep you safe.
It’s also forced schools to actually stock their bathrooms instead of viewing the areas as places the kids mess up that they have to clean. When parents complain (ESPECIALLY at private English schools), stuff gets done. Suddenly there’s soap, toilet paper (I am NOT making this up), and they’re checked with some regularity.
The next challenge: getting over the hysteria that foreigners living in Korea are infected with H1N1 because we cough / sniffle / sneeze / touch ourselves. Oh yes, and NOT using the same ear thermometer to check all the kids temperatures without cleaning it between kids. Again, NOT making this up.
In Pune, India there were maximum number of swine flu cases In India, which started in high schools with kids returning from US/UK summer trips. There is positive effect on people protecting themseves in public by wearing masks and hand washing. Doctors think is good measure for spread of TB. Also, there is less spitting on streets. There is now also a heavy (Rs 1000) fine for spitting !! As TB infection is a major problem in in India, such awareness about mixing in public will certainly help against the spread of airborne deseases.
Losing a job teaches some people that wealth ultimately comes from spending less than you earn instead of from the lottery (“tax on people who are bad at math”) or other get-rich-quick schemes.
Seeing several valuable co-workers lose their jobs in a company-wide RIF will probably have a permanent and positive effect on one of my young relatives, making her both financially prudent in everyday matters, in possession of a written financial plan that she’s already taking concrete steps to implement, and determined to make sure her boss has no possible cause to put her name on the next list.
Nothing makes me quite so happy as hearing a 20-something talk about her goals for her 401(k) plan when so many of her peers are talking about their Macy’s credit cards.
I work in sales for a chemical company, and my revenues have increased nicely with clients purchasing soap, sanitizers, dispensers, and cleansers with the virus kill claim on them… So far its a positive experience!
jacob