*In 2001, union organizers from Local 169 of Unite Here, representing Hispanic grocery workers, reached a labor agreement with Korean business owners. (Photo: Chester Higgins Jr./The New York Times)

Few immigrant groups are as closely identified with an occupational niche as Koreans with grocery stores. While mom-and-pop produce stores have become an engine of economic mobility and opportunity for some Korean families, Korean produce merchants in New York City have often found themselves in conflict with white wholesale distributors, black customers and labor unions representing Hispanic employees, according to a new book by a Queens College sociologist.

The sociologist, Pyong Gap Min, who also teaches at the Graduate Center of the City University of New York, offers a look at the complex role that ethnicity plays in immigrant businesses in New York in the book, “Ethnic Solidarity for Economic Survival: Korean Greengrocers in New York City,” published recently by the Russell Sage Foundation, which finances research in the social sciences.

Among the most interesting insights in the book are Dr. Min’s explanation for why “Korean-black conflicts, which peaked in the later 1980s and early 1990s, have almost disappeared since the mid-1990s,” and his descriptions of how Korean grocers organized themselves to gain more leverage in their dealings with white wholesalers at the Hunts Point Market in the Bronx.

He argues that ethnicity has waned as an organizing principle for the grocers over the years:

Korean greengrocers and other merchants have maintained a fairly high level of ethnic attachment over the past three decades, partly due to their involvement in the ethnic economy. The level of their ethnic solidarity has declined significantly in recent years, however, as their business-related intergroup conflicts have dissipated.

Underlying the book’s themes is the rapid growth in the area’s Korean population. In 1960, there were just 400 Koreans in New York, “a significant proportion of them students at Columbia University,” Dr. Min writes. By 2000, that figure had risen to about 170,500 in the New York metropolitan region, including about 86,400 in New York City.

The easing of immigration restrictions in 1965 prompted the influx. Many Koreans came for advanced graduate training, including medical professionals, while others as family members of Koreans who had already settled here previously. While Flushing, Queens, became the “epicenter” of the New York Korean community, Dr. Min writes, suburban enclaves also sprouted up across the Hudson River in New Jersey, in Bergen County towns like Fort Lee and Palisades Park. The level of immigration has not been constant. The peak year for Korean immigration to the United States was 1987; many Koreans returned home after the Los Angeles riots in 1992, while the 1998 financial crisis in Asia prompted more Koreans to emigrate in search of economic opportunity.

As of 2000, 24 percent of Korean immigrants in the New York metropolitan region were self-employed — the third highest self-employment rate of any group, after Greeks and Israelis-Palestinians (27 percent each). Explaining why Koreans had such high rates of self-employment, Dr. Min notes that many Koreans, despite having good educations in their homeland, face significant language barriers, often knowing less English, on average, than other Asian groups, like Indians and Filipinos.

There were other factors, too. Many Koreans were engaged in business back home. Koreans, starting in the late 1980s, were increasingly able to take capital out of Korea to start new businesses here. Strong family ties and ethnic networks helped them to keep businesses staffed.

Dr. Min writes that grocery stores were the third major Korean immigrant business to emerge since the late 1960s, after wholesale and retail businesses in wigs and other Korean-made goods, and garment subcontracting. (In later years, Koreans established immigrant niches in dry cleaning and nail salon businesses.)

Starting in the 1970s, Koreans bought small grocery stores in minority neighborhoods from retiring white owners, but more often set up new stores by leasing buildings vacated by white business owners. The stores served mostly minority customers: Caribbeans and African-Americans in Brooklyn and Jamaica, Queens, and Puerto Ricans and blacks in the Bronx. (By the early 1980s, some Koreans had begun to set up produce stores in upper-middle-class neighborhoods in Manhattan and Queens and suburban communities on Long Island and upstate.)

The stores were nothing if not labor-intensive — open at all hours in Manhattan, and in the other boroughs, typically from 7:30 a.m. to 11 p.m., seven days a week. Many store owners get up around 3 a.m. to go to the Hunts Point Market. The hours — lengthened by the need to compete with supermarkets and the need to pay rising rents — took a toll:

Because Korean owners of produce stores keep their shops open day and night for seven days a week, they have a few opportunities to see their children. Some see only sleeping children at midnight. Another problem is the danger of armed robbery. Several Korean produce store owners and employees have been murdered during robberies in New York City.

Dr. Min’s book examines the Korean Produce Association, which was established in 1974, opened a service center at the Hunts Point Market in 1980 to support Korean grocers and truck drivers, and became a registered nonprofit organization in 1982. The association has had a litany of complaints about mistreatment over the years at the Hunts Point Market, which opened in 1967 and is the largest fresh fruit and vegetable wholesale market in the United States:

From the beginning, Korean greengrocers and truck drivers were discriminated against and threatened with physical violence, by both managers and employees of HPM distributors. According to interviews with K.P.A. leaders and Korean produce store owners, discriminatory treatment includes higher prices for the same produce items, no exchanges for rotten items included in fruit boxes, refusal to sell hot items after receiving orders, false accusations of theft, discrimination in parking allocations, unreasonably high penalties for parking tickets, and vehicle towing.

The association helped its members to renew business leases, resolve disputes with customers and employees, advocate for police response after armed robberies, resolve excessive competition among Korean business owners, and help members resolve tickets and other government citations. From 1977 to 1995, it organized seven protests against grocery distributors and one, in 1995, against the entire cooperative association that runs the market. The association has also provided its members with programs like help for victims of accidents and a group funeral service program.

But the association’s efforts only went so far. It has tried several times — in the late 1970s, the late 1980s and the early 1990s — to set up a group-purchase system of produce items, Dr. Min writes, but the companies that control the market, largely owned by Italian and Jewish families, mostly defeated such efforts.

While the association “has not been successful in maintaining the group purchase system, it has been very effective in protecting Korean greengrocers and truck drivers from discrimination, mistreatment, and physical violence by suppliers,” Dr. Min writes.

Another major theme of the book is the grocers’ conflicts with black customers and Latino workers.

By the early 1990s, Korean-run groceries had become a significant economic presence in New York’s minority neighborhoods, a process accelerated by the retirement of white store owners and the withdrawal of supermarkets from such areas.

Korean groceries were the target of 15 boycotts by African-American customers from 1981 to 1995, Dr. Min writes. Six of the boycotts lasted for at least four weeks. The longest was a 17-month boycott of two produce stores on Church Avenue in Flatbush, Brooklyn, that began in January 1990.

That boycott — which originated in a physical altercation between a Korean grocery manager and a Haitian customer — escalated into a protracted, and often violent, dispute that drew international attention. It was organized in part by the black nationalist leader Sonny Carson, and it resulted in criticism of the administration of Mayor David N. Dinkins, which did not enforce a federal judge’s order order requiring boycotters to stay at least 50 feet from the stores. Ultimately, Mayor Dinkins paid a visit to the boycotted stores, and a Brooklyn grand jury declined to indict the store manager, and the boycott ended in May 1991, after the owner of the store where the altercation occurred sold it to another Korean immigrant. By banding together, Korean grocers were able to limit the economic effects of the boycotts and to push for intervention from City Hall.

Dr. Min attributed the boycotts to a number of factors, including mutual prejudice, language barriers, frequent shoplifting, the high rates of unemployment among customers, the ideology of “black nationalism,” racial stereotypes about Koreans. But he also said that Korean grocers harbored significant prejudice; a 1992 survey of 93 Korean merchants found that many harbored negative stereotypes of African-Americans as generally less intelligent, lazier, less honest and “more criminally oriented’ than whites.

Why have black-Korean conflicts largely vanished from the news? Dr. Min offers several reasons. In Harlem, rezoning laws have encouraged the opening of big-box stores that have pushed smaller groceries out of business; non-Korean immigrant business owners have increasingly set up retail stores alongside Koreans; and a large influx of nonblacks (who comprised about a quarter of the population by 2000). Moreover, entrepreneurialism is on the decline among the children of Korean immigrants. The children are pushed to pursue higher-status, more lucrative professional and managerial jobs in fields like medicine, law, and engineering.

A less heated, but equally significant, conflict involved Latino workers. Labor unions, state agencies and immigrant workers began to agitate against the grocers in late 1998, culminating in a series of labor disputes between 2000 and 2002. Over all, the merchants were “not able to use ethnic collective action as effectively in their conflicts with Latino employees as they had done with black customers a decade earlier,” Dr. Min writes. But the merchants did negotiate collectively with the labor unions, and also worked to educate their members about labor laws.

In September 2002, the state attorney general, Eliot Spitzer, announced a code of conduct under which Korean business owners would pledge to pay the minimum wage and time and a half for overtime; offer paid sick days and a week of paid vacation each year; and allow investigators to inspect their workplaces and financial records at least twice a year. In return, the attorney general’s office would ignore past violations of labor regulations. About 200 Korean produce owners, mostly in Manhattan, signed the code, but businesses in other boroughs also significantly raised wages for their workers.

Dr. Min’s research was based on interviews of Korean merchants and black and white residents in 1992; a major telephone survey of Korean, Chinese and Indian immigrants in New York City in 2005; in-depth interviews with more than 66 Korean merchants; and personal observations at the Hunts Point market and in three primarily black neighborhoods — Jamaica, Queens, Flatbush, Brooklyn and Harlem; records of the Korean Produce Association; and news articles from three Korean daily newspapers: the Korea Times (New York), the Korea Central Daily News (New York) and the Sage Gae Times.

The book suggests that the phenomenon of the Korean grocery — still considered ubiquitous for many New Yorkers — may prove to be only temporary. By the 2005, there were probably fewer than 1,800 Korean produce stores in the New York-New Jersey area, according to Dr. Min — a significant decline from the early 1990s.