Four weeks ago, I wrote about the dramatic changes in health care that now put Boston City Hospital, the city’s public hospital, at grave risk. It is plagued by declining census and intense competition from Boston’s other hospitals.

A failure to do anything—truly a worse case scenario—will require the city to increase its subsidy for the hospital at the expense of basic city services, education and public safety.

Despite those subsidies, at some point the hospital almost certainly will have to close, meaning a layoff of all its employees and a continuing bond obligation of $179 million.

It is reasonable to ask, in today’s health care environment, whether the notion of a public hospital is outmoded. Rid of the financial and management burdens of a hospital, wouldn’t the city be better advised to spend its resources on public health programs, rather than trying to supplement Medicare, the state’s free care pool, and other programs that provide direct funding for care?

The answer probably is yes. But the fact is that Boston does have a hospital, one with a large mortgage. Burdened by decisions made in the past and constrained by a dynamic and freewheeling health care marketplace over which it has no control, the city has no perfect solution available to it.

The second best solution is to try to reduce the hospital’s cost to Boston and at the same time make every effort to allow it to remain a viable entity.

This is the kind of solution the Mayor has proposed: merging BCH with Boston University Medical Center and creating a new hospital entity called the Boston Medical Center. Both BU and the City would put virtually all of their hospital assets into the new entity and also provide continuing subsidies to keep it solvent.

The new merged entity would be less of a financial drain to Boston and would have a better chance than the stand-alone hospital of succeeding as a health care provider. As illustrated in the tables below, the new entity should be able to achieve better than break-even in five years according to a study by Coopers & Lybrand. And the net costs to the city are lower: $324 million in subsidies over five years versus $390 million if nothing is done.

However, it is important to note how these dramatic improvements are obtained. The new hospital succeeds because it is a private entity, free from the political and civil service constraints that have hampered Boston City Hospital.

It becomes more efficient because it downsizes and consolidates: over the first five years, 1,300 employees will lose their jobs—about 900 through attrition, the remainder receiving pink slips.

And a critical component of its success is its ability to establish good sources for patient referrals, the so-called HealthNet, which is a group of neighborhood health centers that have committed to send their patients to Boston Medical Center.

It very well may be the case that the new entity cannot do as well as projected. Count me as one of the pessimists. Indeed, I would not be surprised if several years from now we saw new proposals aimed at merging the Boston Medical Center into one or more of the city’s other hospitals.

But today’s issue is relatively straightforward. Does the city give BCH a fighting chance to succeed, or does it do nothing, thereby dooming it. Many other city councilors have called their vote on the merger the most difficult decision they may ever make. I disagree. I think it is an easy vote.