When did New Yorkers start thinking density was bad? Maybe it was around the time many commentators stopped actually reading Jane Jacobs and started relying instead on a few famous quotes. Even as she has been elevated to cult status, the subtleties and complexities of her positions have often been glossed over.

For one thing, Jacobs loved density and concentration—and disdained dispersal and decentralization.

Early in The Death & Life of Great American Cities Jacobs gleefully announces that housing activist Catherine Bauer has devised the perfect term for attacking regional planners like Lewis Mumford: Decentrists. The Decentrists urged decentralizing the great cities like New York. They wanted to thin them out, disperse their enterprises, disband their populations into smaller, separated cities. Decentrists thought urban streets were bad environments for human beings. They recommended turning houses away from the street—even though facing the street was fundamental to the classic early American housing form. Instead, they advocated turning houses inward toward sheltered greens. They believed the basic unit of urban design to be not the street but the block, especially the superblock. Commerce, they argued, should be segregated from residences and parks. And it should be limited according to scientific calculations of the residents' demand for goods and services.

Somehow these ideas came to dominate mainstream thought until Jacobs blew them away in D&L. Jacobs understood that density provides critical mass. Density means good stores, good services, cafes, and restaurants. It also means street life and round-the-clock activity—all of which means safety. The city is safe these days not only because the New York Police Department has fought crime strategically but also because the streets are full of people day and night.

The idea that density is good was one of Jacobs's most important contributions. As she wrote in D&L, "There must be sufficiently dense concentration of people, for whatever purposes they may be there. This includes dense concentration in the case of people who are there because of residence." And within this critical concept lie several others.

RESPECT THE WORKING CLASS AND THEIR EXUBERANT NEIGHBORHOODS
Jacobs's most important urban lab was Greenwich Village, the ultimate dense but basically low-rise, working-class neighborhood. Small-town girl that she was, she took her lessons on proper urban behavior from her neighbors: Joe Cornacchia, owner of the corner deli, who kept her keys for visitors and emergencies; Bernie Jaffe, owner of the candy store, who guided small children across the street and reprimanded rowdies on bad behavior; Mr. Lacey, the locksmith, who bawled out Jacobs's son for running into traffic and reported him to his father; and so on—Mr. Koochagian, the tailor, Mr. Lofaro, the fruit man, Mr. Halpert, the laundry man. The Village's ethnic street ballet dances on.

It can be hard to remember today just how revolutionary it was of Jacobs to respect and celebrate working-class households and their conservative, old-world but socially attentive morals. Ethnic neighborhoods were emptying out into the suburbs, either voluntarily via financing mechanisms like the GI Bill or coercively under urban renewal. Either way, most intellectuals writing on cities were glad to see them go, making way for enlightened progress. Jacobs saw tragedy in their exit. She admired not only their territoriality but their commerce—delis, trattorias, taverns, hardware stores—enterprises that were often held in contempt as too parochial and insignificant both by the intellectual elite of the times and by government officials. Equally important, she cheered the development patterns by which work was mixed in naturally and continually with residences.

LET PEOPLE WORK WHERE THEY LIVE
Until the mid-20th century, when zoning started rigidly categorizing and segregating uses, most New Yorkers worked close to where they lived— sometimes in the same building. Not only did this development pattern encourage the kind of street liveliness Jacobs admired, it was also efficient and family-friendly, allowing people to walk to work and return home for lunch if they chose. It was a supremely green form of development—much appreciated today by a range of groups from New Urbanists to industrial retention advocates. Yet it is largely banned by the city's zoning code.

Called Zero Commute Housing in some sections of the country, Live-Work became a national movement in the 1970s—but has never been truly embraced by any New York mayoral administration. Nor is it even much discussed these days by Jacobs's many fans, perhaps because she was writing before New York’s catastrophic 1961 zoning resolution, which forbade residential construction or renovation in manufacturing zones. And that same resolution expanded manufacturing zoning deep into formerly residential neighborhoods, hastening their decline even as manufacturing jobs decreased for the many familiar secular reasons. Mixed-use districts could work very successfully up and down the waterfront—witness how successful the limited live-work developments in Red Hook, Brooklyn, have been.

RETHINK PUBLIC HOUSING
Jacobs opposed virtually all single-use development, but particularly what she called "massive public housing projects" that "tend to cause their city surroundings to deteriorate." As the blocks around public housing decline, the result is that "as time passes, less and less healthy adjoining city is available to tie into."

In her admiration of cities as "delicate, teeming ecosystems" Jacobs disdained public housing projects as places of concrete monocultures deliberately designed without the functional and commercial diversity she admired. The street-level merchants who kept traditional neighborhoods safe both by their watchfulness and the activity they promoted were typically obliterated by urban renewal—leaving public housing tenants bereft of grocery stores, restaurants, or services.

Indeed, decades after Jacobs wrote "Death and Life" most New York City Housing Authority buildings still have no retail or business services. Of its 343 developments, only 28 offer commercial leases. Certainly the NYCHA should be rethinking its commercial policies that somehow deprive the vast majority of its residents of basic retail services. But neighborhoods, for their own health, should also be pressing a retail rethink on NYCHA. After all, New York distributed public housing projects throughout the five boroughs, which means that all New Yorkers have an ongoing interest in what happens in public housing.

LET A THOUSAND VENDORS BLOOM
In bemoaning the stagnation of Lower Manhattan—and accurately predicting its further deterioration—Jacobs commented that "almost every unique appeal to visitors that could possibly be rooted out of this district by plan has been rooted out." She lamented the destructive removal of the aquarium to Coney Island by Robert Moses, the relocation of the "strange and vital little Armenian neighborhood" to Brooklyn, and the appalling, sterile lack of appeal of the Parks Department's concessioned snack bar in Battery Park, which she called "the most stirring location in the city." This government-imposed sameness of services accelerated the area's already serious decline.

These days, nearly everyone agrees on the importance of Jacobs-style diverse commercial activity—most obviously seen in the world of food. In a brilliant stroke, the Rockefeller Foundation has just bestowed its Jane Jacobs Medal on Barry Benepe, the co-founder of Greenmarket, the largest farmer's market in the country. With markets in over 30 neighborhoods (including parks) in the five boroughs, Greenmarket was modeled on centuries of traditional farm-to-city open-air market places, said Benepe in his acceptance speech. Some 100 of the city's best restaurants now shop at Greenmarkets, benefiting themselves, their customers, and local farmers. Meanwhile, the Parks Department, headed by Barry Benepe's son, Adrian, is grappling with a heritage of concession policy that almost inevitably wipes out "almost every unique appeal to visitors," particularly in food. The food vendors of Brooklyn's once-deserted Red Hook Park, acclaimed for years both by official food critics and by the attentive food blogosphere, are at the very heart of Jane Jacobs's vision for New York—ethnic households supporting themselves financially by producing and selling their foods from home. Vendors from Mexico, El Salvador, Honduras, Ecuador, Chile, etc. sell ceviche, papusas, baleadas, huaraches, taquitos, and tamales to long, snaking lines of people. But they lack a contract to be on Parks Department property and have never, of course, participated in the city's official Request-for-Proposal process. The Parks Department's concession division had been threatening to make the vendors compete with the department's usual food service providers. Of course, they would lose. Commissioner Benepe has rightly stepped in with a stay of execution, and a pledge to work with them to devise a system for permanent status. This won't be easy, but then few of Jacobs's solutions have ever been easy.

WHAT’S NEXT
The Municipal Art Society is sponsoring a series of talks and walking tours that will examine "Jane Jacobs and The Future of New York." These events, which take place from October 3 through December 4, give every New Yorker an opportunity to read Jacobs's writings and reflect on her ideas—which may well yield a public debate and reconsideration of the many public policies that have barely evolved since 1961, when D&L was first published.