At Mayor Bill de Blasio’s January 1 inauguration, speaker after speaker cataloged the inequalities of 21st-century New York (which are real, but would provoke envy in Oliver Twist). There were frequent references to the city as it existed before Mayors Mike Bloomberg and Rudy Giuliani; we were wistfully transported back to the days of Fiorello La Guardia and David Dinkins, when New York was just about piss and grime, not piss and grime and runaway wealth.

The shorthand for that New York was once “the bad old days.” In 1990, during Dinkins’s tenure, an astonishing 2,245 murders were committed in New York City, compared to 332 last year. How this precipitous decline in violence was achieved is a matter of intense debate—CompStat, broken windows policing, gentrification, abortion—but let’s leave that to the social scientists and acknowledge that the bad old days have long since past. A good development, one would think. But de Blasio’s inauguration was suffused with nostalgia for the bad old days. Indeed, the reflexive nostalgia for uglier, more “authentic” times infects most conversations one has about New York with other New Yorkers.

And it isn’t just New York. Everywhere, everywhere, one finds pessimism about the future, despite declining violence; rising wealth in India, China, Vietnam, and other once poor countries; and jaw-dropping advances in science and technology. The world is a vastly better place than it was 50 years ago.