The trouble with using a liquor-by-the-drink tax to support the Philadelphia public schools is that there's a natural temptation to look for ways to keep tavern patrons perched on their bar stools longer.

So, along comes a proposal from City Councilwoman Blondell Reynolds Brown to let bars stay open an extra hour - until 3 a.m., rather than the 2 a.m. closing time that's the rule in most cities across the country.

Brown estimates the extra 60 minutes at the brass rail would mean the city raises an additional $5 million each year through its 10 percent per glass tax on retail sales of liquor, wine, and beer.

Along with the roughly $42 million generated annually in recent years by the liquor tax, the extra funds could help the School District cope with a $61 million deficit this year.

With even worse fiscal problems predicted for the schools by City Controller Alan Butkovitz, it's clear that Brown, her Council colleagues, and Mayor Nutter need to be focused on such strategies to bolster schools funding.

As Brown noted in making her proposal Thursday, it doesn't appear likely that Gov. Corbett or Republican-led state lawmakers will come to the schools' rescue with their no-new-taxes mind-set and more budget cuts expected in Harrisburg. She's also wise to steer clear of yet another major local tax increase, following increases in the sales tax and a double bump to property rates.

Unfortunately, Brown's late-closing plan is a fund-raising idea that may not be painless. Aside from promoting drinking, there are potential public-safety risks and the increased costs of policing perhaps rowdier bar patrons who spill out onto downtown and neighborhood streets later.

While it's true that New York and some other major East Coast cities have later closing times, a Scandinavian study produced the sobering finding that violent crime jumped by 16 percent for every additional bar hour.

The horrific fatal beating in mid-January of a man who'd left a Center City bar was an extreme example of post-closing crime, to be sure. But given the city's spate of recent murders - mostly shootings - this seems like a particularly bad time to risk making any mean street meaner.

Even if Council were to adopt Brown's measure, the later closings wouldn't take effect without the state's blessing, which is being sought through legislation sponsored by State Rep. Vanessa L. Brown (D., Phila.).

For her part, the councilwoman agrees the late-closing idea needs to be shaken, and even stirred, with debate before it's served up. In the process, let's hope Council realizes this extra time would not be a happy hour for the city.