On matters of land use, Philadelphia City Council members have long deferred to the wishes of the member whose district includes the land in question, a collegial practice known as "councilmanic prerogative."

A new report released Thursday by the Pew Charitable Trusts shows just how firm that tradition's footing is.

In recent years, Council has never voted against a district member's wishes. Of 730 land-use decisions over six years, the report said, all but four passed unanimously.

"The use of councilmanic prerogative, when invoked by a district Council member, is unfailingly honored by the rest of Council, even in those cases when the project is widely considered to be of citywide import," said Larry Eichel, director of Pew's Philadelphia research initiatives.

The report, completed in partnership with the website Plan Philly, does not pass judgment on the practice. But it does note that councilmanic prerogative is often invoked behind closed doors and not clearly marked in a public record, creating the potential for unethical behavior.

While the vast majority of transactions are aboveboard, the report noted that land use played a central role in the six cases since 1981 in which Council members were convicted of wrongdoing. And it cited unnamed developers as saying Council members use the power to draw in campaign contributions.

The Pew findings come as the city is struggling with how to dispose of its large inventory of properties, many vacant and blighted.

The Philadelphia Land Bank, one recent initiative, was intended to make it easier for properties owned by various agencies to be sold together or put to good use, but has struggled to launch. Councilman Mark Squilla last month bypassed the bureaucracy and held an auction, raking in $1.78 million on 89 lots in just a few hours.

Councilmanic prerogative allows Council's 10 district members broad discretion over land use in their districts. But it mostly comes into play during the disposition of city-owned land and on zoning issues, including when a developer is seeking a change needed for a specific project.

The practice has drawn criticism that it creates a lack of accountability. Its defenders say it allows Council members who know their districts to intercede on projects that could have a large impact on surrounding neighborhoods.

"Nobody knows a community better than the district Council person that represents it," Council President Darrell L. Clarke said in the report. "It's just the simple reality."

Among other findings, the Pew study found:

Developers, both for-profit and nonprofit, said Council members use the prerogative to "reward political supporters, punish political enemies, and generate campaign contributions." The report did not elaborate.

The Land Bank is not yet operational, but under its proposed structure, potential buyers need to receive a letter of support from the district Council member - codifying the now-informal practice of councilmanic prerogative into law.

Council members often use the power to block sales of city-owned lots, at least temporarily. But it is unclear if that councilmanic prerogative is a major contributor to the storied slowness of the land disposition process in Philadelphia. In many cases, researchers found, the delay actually happened after Council had approved a parcel's sale.

Councilmanic prerogative, known elsewhere as legislative courtesy, is common in other cities. But the practice is more robust here than in places such as Chicago and New York City, because of factors such as Philadelphia's being essentially a one-party city, its vast stock of publicly owned land, and Council's long-established power to adjust zoning.

Thwarting 'a larger vision'?

The report noted several large projects that had been caught up in councilmanic prerogative over recent decades - the Liacouras Center at Temple University, the SugarHouse Casino, and the Juvenile Justice Services center in West Philadelphia.

Lawyer Thomas A. Leonard, reacting to the study, recalled Thursday that developers he represented had seen a project derailed by opposition from community groups and, in turn, a district Council member. He said the prerogative becomes problematic if a project that can benefit the wider city - as he says his clients' would have - is blocked because of concerns in one district.

"It enables a group with a small vision related to their own personal needs to thwart what might be a larger vision for the city," he said.

Leonard, a former city controller, noted that the seven at-large Council members are supposed to represent the city as a whole, but that they yield to district Council members' wishes.

David Thornburgh, president of the independent watchdog group Committee of Seventy, said he worries that developers will choose to build in nearby communities to avoid the political process here.

Thornburgh voiced surprise at the extent to which a "professional courtesy or habit or custom" appears to be "increasingly recognized as near law."

"It's easier to think about how you'd repeal or change a law," he said. "It's another thing to figure out how you could change a well-accepted custom."

'Serious business for us'

Clarke said in a statement that all Council votes on land use are public and that the group "has made significant strides toward a more efficient and transparent land disposition process, namely with the creation of the Land Bank, and continues to work with the administration and community stakeholders toward equitable redevelopment across the city."

And not everyone thinks the policy needs changing.

Asked if the prerogative can breed problems, Councilwoman Jannie L. Blackwell said Council votes unanimously because members trust that their district colleagues have done their homework.

Blackwell, whose West Philadelphia district has among the most city-owned lots of any of the 10 districts, said she deals each week with myriad land-use issues, ranging from a developer who wants to put a three-story building among two-story homes to neighborhood opposition to a new business.

She said that those who criticize the practice think Council members make their decisions frivolously, but that this could not be farther from the truth.

"It's not a matter of what we want," she said. "It's a matter of representing their communities. . . . 'Prerogative' is whether I eat chocolate cake or vanilla ice cream tonight. This is serious business for us."