VACCINE UPDATE: “Measles cases in the U.S. are at the highest level in more than a decade, with nearly half of those involving children whose parents rejected vaccination.” Gee, go figure. I had a column on the subject earlier this month.

UPDATE: Reader Cheryl Drury emails: “Your PM column about vaccinations and your earlier post on making traffic safer have me thinking…How does the perception of danger affect our behavior? When people knew the danger of measles, they jumped on the vaccine eagerly. When the roads and intersections looked dangerous, people drove more cautiously. How does this affect our behavior in other ways? I’m thinking the higher drinking age and defense spending. Also, what about the flip side…where you perceive too much danger and don’t let your kids outside to play in the front yard? There is a huge thread to put together there.” Yes.