I was wandering around Harlem recently, late on a warm Sunday afternoon: I saw Dominican families chatting on stoops. I saw African-American families walking home from church. I saw a Cuban-Chinese deli and popped in to buy a refreshing something-or-other that resembled a mango egg cream. I saw a busload of Japanese tourists. And I saw lots of young white families unloading weekend gear from Jeep Cherokees lacquered with Bridgehampton beach stickers, their tanned and tousled children wearing sweatshirts with the names of the world’s most expensive private schools emblazoned upon them. It was a pleasant stroll, the sort of thing that makes me glad to be living in New York. Indeed, at this particular moment, Harlem may be the most racially, ethnically and class-integrated neighborhood in the world. This is good news. The question, of course, is whether it will stay that way.

As with all of Manhattan, Harlem’s real estate prices have suddenly gone through the roof. Burned-out shells of brownstones go for half a million, while pristine specimens are listed in Sotheby’s International. Like most, I am glad for the increased desirability of a Harlem ZIP code. But I wonder if there are not a few cautionary reminders one might bring to bear.

The most obvious concern, as one reads breathless newspaper accounts of square footage, is a certain otherworldliness in tone. “Urban pioneers” is the term most often used to describe the largely white families who are moving into this historically black area. No matter that Harlem has always had a substantial black middle class, a stable working class and eminently respectable social systems; the popular imagery is that of brave white settlers in their SUVs (doors locked, windows up) traveling in cautious cavalcades to homestead the wild, heathen emptiness.

By all accounts, Harlem is “in transition.” If one pokes at that terminology just a little bit–transition from what to what?–one uncovers rather broad assumptions that Harlem is progressing from a state of “blight”; that it is being “redeemed” with new faces, new stores, new investment; and that its ultimate destiny is to be “reclaimed” by those who have made the rest of Manhattan so trendy that an average apartment now costs well over $700,000.

I guess I hope for a number of things. First, I hope that gentrification stops short of Trumpification. As invisible as it has been to many, Harlem’s class diversity has always contributed to its vibrant social, cultural and political life.

Second, I hope the new movement to Harlem signals a reversal of the abandonment of inner cities. I hope it signals an era of racial diversity, true tolerance for propinquity and not merely the corollary of white flight–the strategic displacement of black and brown populations. I do not mean to impugn the neighborliness of any of the new residents of Harlem. I am more concerned about the larger institutional manipulations that have contributed to the stark consequences both of white flight and, now, white reflux.

When Northern whites grew afraid of the migrations of blacks from the South from the thirties through the seventies, it was the National Association of Realtors that calculatedly fanned that fear into a panic, realtors going door to door warning that the property values were falling, falling: Sell now while you can. In city after city, the story was the same: Whites, terrified that the end of civilization was nigh, sold low. Blacks, believing they were purchasing the dream of integration, bought high. The realtors made a killing. The newly segregated neighborhoods went into quick decline as services of all sorts were summarily withdrawn–schools, snow removal, grocery stores, bus lines, police. Banks wouldn’t finance home repairs; assessments plummeted; crimes went uninvestigated and thus flourished. Insurers, if they insured at all, charged sky-high rates supposedly based on greater risk, then failed to pay for actual losses.

Today a new breed of real estate speculator has fanned the “buzz” that is changing Harlem so rapidly. Thanks to complicated incentive programs and community empowerment zoning, banks, too, have begun funneling money back into communities that they had historically redlined. But the degree to which these new financial policies improve the lot of Harlem’s low, moderate and middle-income populations–or simply drive them out–remains to be seen.

In recent months the City of New York has sold many of its Harlem properties to developers whose interests do not always overlap with those of longtime residents. Consider the tension: I have friends struggling to find immediate financing for the house they have lived in for thirty years. I, on the other hand, received a form letter offering Columbia University faculty very favorable loan terms for housing in Harlem.

In this rush to go upscale, I hope that policy experts and institutional investors do not diminish–with such terms as “blighted”–the role of long-term stable populations, whose insistent struggles have produced the lion’s share of the recent turnaround. In using the word “stable” one is often understood to mean church-going, college-educated, middle-class residents with steady incomes. But by “stable” I also mean to include working-class and poor families, people with extended families, with several adults in and out of work, homes where a grandparent or aunt helps make ends meet by looking after their own and the neighbors’ children. These are the populations who suffered most from the lack of local grocery stores, for example, and who pressed for the new Fairway market in Harlem–a store so magnificent that Wall Streeters travel the length of the city to stock up on guavas and fresh rabbit filets. These are the families who suffered simultaneously from high crime rates and suspect profiling and whose protests made policing tactics a national issue. These are Manhattan’s messengers, hospital workers, fast-food servers, secretaries, janitors, nannies and security guards whose tenacious political passion about issues such as education, healthcare and garbage removal have made them models of community engagement.

For all these good things, greater credit–both literally and figuratively–is most assuredly their due.