El Salvador is rightly famed for its strides on public order, but most people don’t grasp the brutal extent of previous gang rule or the complex dividends peace affords. All kinds of mundane and essential public goods re-materialize now that people can walk around, ride transit, and go about their lives without being terrorized. This historic square used to be patrolled by warring gangs, and housed an informal economy of corrugated-tin shanties where subsistence street vendors forfeited much of their meager income to “protection” rackets. No formal economy is possible if thugs might burn or smash or sabotage any capital improvement you make. Now, there are ordinary shops lining this downtown area — and even early Christmas decorations.