Every few years, I write a column about the United States Postal Service. In 2009 I just about wrote it off. That year the Postal Service faced a $7 billion revenue shortfall, and 700 post offices were slated for closure.

The problem wasn’t inefficiency or mismanagement. The previous year the post office had delivered 212 billion pieces of mail — 46% of the world total — with an on-time delivery rate between 94 and 97 percent.