When Kang Young Oh first came to America from South Korea in the early ’80s, he put to work the one asset he had his family.

First there was the fish restaurant, where his nephew prepared the sushi, his wife managed the finances, and he and his three school-age children waited on customers.

Now Kang and his wife, together with their grown son, operate Jack’s Liquor on Olympic Boulevard. Do the Kangs work as a family simply because they enjoy each other’s company? Well, not really.

“It’s a matter of survival,” Kang says. “If business was better we’d probably separate and go into different fields.”

It is a scenario played out across L.A.’s Asian and Latino communities, where family-owned and operated small businesses are the norm.

“In Koreatown, if the company is not a branch of a larger Korean company it is almost certainly a family business,” said Harrison Kim, executive director of the Korean American Chamber of Commerce of Los Angeles.

While the close-knit nature of Asian and Latino families is the most obvious explanation for the high proportion of family businesses in these neighborhoods, there is at least one more compelling reason economic necessity.

Asian and Latino communities are dominated by so-called “micro” businesses. Of the roughly 300,000 Latino-owned businesses in L.A. County, as many as 90 percent employ fewer than 10 people, according to various sources. Up to 75 percent of the 140,000 or so Asian-owned businesses in L.A. have 10 or fewer employees.

For owners of many micro businesses such as liquor stores, groceries, launderettes and tailor shops the margins are slim and the hours long, particularly for those in low-income neighborhoods.

As a result, bringing a family member on board, who usually will work longer and harder and forego a salary in lieu of a stake in the business, can be a key to survival.

“It has allowed us to succeed without a lot of start-up capital,” said Nadine Trujillo, who together with her two daughters runs a Mexican restaurant called Alegria in Silver Lake. “Otherwise we might have had to close our doors.”

That pressure is felt the greatest by immigrants, especially those from Asia and Latin America, who typically have limited money and language skills. As a result, their options often boil down to either earning minimum wage doing manual labor or opening a small business. The latter is often seen as the more attractive alternative, especially if family members can be put to work for little or no cash.

“There are three main sources of wealth: capital, land and labor,” said Fernando Guerra, director of the Center for the Study of Los Angeles at Loyola Marymount University. “Most immigrants don’t have capital and land. The one thing they do have is labor, in the form of their family.”

Besides being willing to work for little or no cash, family members tend to work longer and harder than hired hands, a factor that can make or break a small business.

“If you work with family, they take care of the shop, they don’t throw away food and they are good to the customers because it is a family business,” said Jack Demoulian, an immigrant from Armenia who operates a catering truck business, Jack in the Truck, with his wife on Wilshire Boulevard.

While the number of family-run businesses in the Asian and Latino communities likely will decline over time, especially as second- and third-generation offspring of immigrant families enter the workforce, opinion varies over how fast and to what degree that transition will come.

Niton Bhatt, director of the USC Business Expansion Network, which provides technical support to small businesses, argues that as long as Latinos feel a sense of exclusion from mainstream American culture, there will be a tendency to depend more on their extended families when it comes to doing business.

“Latinos feel that the only way they can succeed is through cooperation between their own people,” he said. “That creates a scenario that leads to more family business.”

The Asian-American pattern is not easy to generalize. Countries such as Indonesia and Korea have long histories of family-run business dynasties; even today, major publicly traded corporations in Indonesia, Korea and elsewhere are run by family dynasties. As a result, even after they have been assimilated into the local culture, Asian Americans may be more likely to keep business within the family.

That scenario did not hold true, however, for Japanese Americans, most of whose ancestors immigrated to this country in the first half of the century.

While the Japanese also have a tradition of close-knit families and family corporate ownership similar to that found in Korea and elsewhere in Asia, Japanese Americans today appear no more likely to enter into business with their immediate family than are L.A. residents of European ancestry.

“It’s a one-generation phenomenon,” said Joe Wakabayashi, a second-generation Japanese American living in Los Angeles. “My dad had me working in his laundry every day after school. But if I tried that with my kids, there would be resistance.”