CHARLIE’S FATE may be still unlearn’d, but he surely had to leave the train when Boston discontinued its all-night service 50 years ago. If the Kingston Trio were singing an MBTA anthem today, it would probably be protesting the death of night owl service. But late night trains are expensive and the MBTA is already heavily subsidized, which means that options will require compromise and creativity.

Night owl transit would help give Boston the energy of a 24/7 city, say proponents. Boston is virtually alone among major metropolises in shutting down its subways so early; New York City and Chicago have trains running all night, while Philadelphia extends its subway service to 24 hours a day with its NiteOwl bus service. Advocates also emphasize the dangers of drunk driving, and the poorer restaurant employees who need to get home after a long night serving their wealthier clientele.

Late night service would make the city more exciting — if it can be provided without extravagant subsidies. From 2001 to 2005, when the MBTA offered night owl buses serving train routes from 1:00 to 2:30 a.m., the cost came to about $8 a ride. At that price, free cab service looks pretty good. Facing budget woes, the MBTA ended the program five years ago.

The MBTA recently estimated that the annual costs of providing late night Friday-Saturday bus service along key train lines would be more than $2.1 million. Manpower , not materials, represents the lion’s share — 84 percent — of these costs. The biggest single category is the $606,000 in wages paid to provide 100 person-hours of bus operators over 104 nights. Three inspectors will cost another $197,000.

Late night service is particularly expensive because the bus drivers have to be paid double-time for working late at night, which makes their average wage $58 an hour. The MBTA doesn’t break out fringe benefits for the operators, but it estimates that benefits, FICA, and pensions add an extra 69 percent to overall labor costs. If that rate applied for the bus operators, they would be earning $98.02 an hour. Few cab drivers earn that kind of money, which is why cabs seem inexpensive relative to late night transit service.

Paying those costs requires enough riders, which pushes toward serving the lines that historically garnered the most ridership. When the service was initiated in 2001, the MBTA ran 17 night owl lines, but more than one-half of the 1,600 riders per night came on just four: three following Green Line routes and one on the path of the Red Line.

Late night service also becomes more feasible with higher fares. It does seem reasonable to ask travelers to pay a few extra dollars for the privilege of riding late at night. But the higher fares deter ridership, so more creative options should be explored.

One possibility is that interested parties — the large schools that would be served by night owl buses and entertainment venues — could buy night-time ridership passes in bulk and then distribute them. Perhaps a reformed liquor licensing system would require liquor licensees in served areas to buy significant numbers of tickets that they could distribute to their customers as a perk.

The purely public option deserves more attention, but so do private options that could provide drivers at less than $100 an hour. The MBTA could arrange for private late night jitney service along key routes. Private jitneys could be flexible and cheaper, since providers could pay private sector wages. With enough regulations, the jitneys would be safe and comfortable. The big problem with any private solution is the Pacheco Law, which limits private provision of public services. But the law arguably doesn’t impact taxis, which raises the hope that a late-night jitney system could be created within the Pacheco limits.

Late night transit service would be a boon for Boston. It would be terrific if the MBTA could manage a way to do this with limited subsidies, but we should also be open to private options, especially on routes that cannot be affordably covered by public service.

Edward L. Glaeser, a professor of economics at Harvard University, is director of the Rappaport Institute for Greater Boston. His column appears regularly in the Globe.

© Copyright 2010 Globe Newspaper Company.