Monday night, for the first time in the 110-year history of New York City’s subways, the system was shut down for a snowstorm. Tuesday morning, with eight inches of snow on the ground in Central Park as of 7 a.m., that decision is looking pretty unnecessary.

At a news conference this morning, Gov. Andrew Cuomo characterized the subway closure as a “decision to err on the side of caution." The thing to remember about these sorts of decisions is that caution can be really expensive.

As of 2014, there were 3.9 million people working in New York City, earning an average daily wage of $409. A majority of those workers commute via the city’s public transit system, even when the roads are in good condition. If the subway closing led just 10 percent of people who work in New York City to take the day off today, the cost in lost labor was around $160 million — lost wages for those who are not fortunate enough to get a paid snow day, and lost productivity to the employers of those who did get paid without working.

Of course, you have to weigh that cost against the cost of being caught unaware in a snowstorm that’s really big. This storm could have hit New York as hard as it hit Boston. This was a good reason for a road travel ban; as Mr. Cuomo noted at the news conference this morning, unexpectedly high snowfall in Buffalo in November stranded many people on roads for hours.