so would result in deportation or a fine of up to 5 million piastres. As most ethnic Chinese in Vietnam were holders of ROC nationality in 1955, the measures greatly reduced the number of expatriate Chinese in South Vietnam. The fourth decree in particular had the effect of encouraging Chinese businessmen to transfer their assets to their local-born children. In 1955, the number of ROC nationals stood at 621,000, which was greatly reduced to 3,000 by 1958. The South Vietnamese government later relaxed its stance to foreign-born Chinese in 1963, and a new nationality law was passed to allow them the choice to retain their ROC nationality or adopt South Vietnamese citizenship. The following year, the Statistics Office created a new census category, "Nguoi Viet goc Hoa" (Vietnamese people of Chinese origin), whereby Vietnamese citizens of Chinese heritage were identified as such in all official documents. No further major measures were implemented to integrate or assimilate the Chinese after 1964. Departure from Vietnam: 1975–1990 Following the reunification of Vietnam, the Hoa bore the brunt of socialist transformation in the South. The control and regulation of markets was one of the most sensitive and persistent problems faced by the government following the beginning of North–South integration in 1975. The government, in its doctrinaire efforts to communize the commercial, market-oriented Southern economy, faced several paradoxes. The first was the need both to cultivate and to control commercial activity by ethnic Chinese in the South, especially in Ho Chi Minh City (formerly Saigon). Chinese businesses controlled much of the economic activity in Ho Chi Minh City and South Vietnam. Following Vietnam's break with China in 1978, some Vietnamese leaders evidently feared the potential for espionage activities within the Chinese business community. On the one hand, Chinese-owned concerns controlled trade in a number of goods and services, such as pharmaceuticals, fertilizer distribution, grain milling, and foreign-currency exchange, that were supposed to be state monopolies. On the other hand, savvy Chinese entrepreneurs provided excellent access to markets for Vietnamese exports through Hong Kong and Singapore. This access became increasingly important in the 1980s as a way of circumventing the boycott on trade with Vietnam imposed by a number of Asian and Western Nations. An announcement on 24 March outlawed all wholesale trade and large business activities, which forced around 30,000 businesses to close down overnight, followed up by another that banned all private trade. Further