Although Mayor Rendell may have put the city back on its feet, there is no assurance that it will remain there.

We will hear a lot about who can best lead the city. Can we cut through the rhetoric to determine who may be the best candidate to help steer the Philadelphia economy into the next millennium? Yes. All we need is some basic economic principles to guide us.

The first and most important fact that everyone should recognize is:

As good and well-intentioned as a mayor may be, he or she cannot control the economy.

Am I really saying that the current economic strength in the city is not the direct result of the current mayor's actions? To a large extent, yes.

Without what is becoming the longest national economic expansion in history, Philadelphia would be suffering dearly. National, international and regional economic trends and patterns determine the general economic environment in which the city must operate, not a mayor.

History tells us that Philadelphia tends to move into a downturn before the nation and recover more slowly. Had there been a recession recently, we'd be talking about getting out of another fiscal mess rather than what we might do with the budget surpluses of the last five years.

Which brings us to the second truism:

You cannot do much without money. Sound fiscal policy is the basis from which all government policies flow. While it might be nice to be able to run deficits as the federal government used to, the city cannot. And even if it could, the benefits of a surplus and the flexibility it provides are obvious. Just look at what is happening in Washington.

If the next mayor is to try to address problems such as public education, crime and the quality of life for the residents and businesses of the city, he must do so from a platform that is fiscally stable. Anything less will leave the city exposed, especially when the next downturn occurs. Let's remember that when we evaluate each candidate's position on how to handle the city employees' contract negotiations.

Does that mean that all a mayor can do is run a tight financial ship? Absolutely not, but what he can accomplish has to be tempered by this reality:

The budget must be balanced.

The requirement of fiscal restraint should be viewed as a liberating factor, not a constraint on policy. Since the politically popular but forever failing big-ticket projects cannot be funded, they shouldn't be proposed. Let's look for projects that lay the foundation for the future.

Consequently, the next mayor must become truly imaginative. The city has a ton of problems, and thinking traditionally will not solve them.

To be successful, the next mayor must:

Understand the global trends that are driving the economy.

Identify the city's strengths and use them to support those trends, even when policies may not seem to make sense or more critically, even when they may take many years to bear fruit. Ribbon-cutting is fun - building a lasting prosperous economy takes time.

Harness the current changes in the economy because you can't prevent change. For example, if a business threatens to leave and if that business really doesn't have a real economic reason for staying, sometimes you just have to say good-bye. Letting firms leave is not popular, but it can make sense. By not squandering economic funds on lost causes, more resources remain available to retain and attract those businesses that can succeed, both in the Philadelphia environment and in the Internet economy of the future.

So, who can best lead the economy of the city? Not the candidate who tells us he'll create lots of jobs or rebuild all the neighborhoods or make sure every student is prepared to get a Ph.D. It is the person who can best explain how the city's key attributes, along with the changing world economy, can be employed over the next decade to make Philadelphia the destination for people and businesses. The candidate that can give voice to a clear vision of the economic future is the one to take the city into the next millennium.