source of investment funds from government budget allocations, which carried no interest and did not have to be repaid, to interest-bearing bank loans. As of 1987 the interest rate charged on such loans was still too low to serve as a check on unproductive investments, but the mechanism was in place. The role of foreign trade under the economic reforms increased far beyond its importance in any previous period. Before the reform period, the combined value of imports and exports had seldom exceeded 10 percent of national income. In 1969 it was 15 percent, in 1984 it was 21 percent, and in 1986 it reached 35 percent. Unlike earlier periods, when China was committed to trying to achieve self-sufficiency, under Deng Xiaoping foreign trade was regarded as an important source of investment funds and modern technology. As a result, restrictions on trade were loosened further in the mid-1960s, and foreign investment was legalized. The most common foreign investments were joint ventures between foreign firms and Chinese units. Sole ownership by foreign investors also became legal, but the feasibility of such undertakings remained questionable. The most conspicuous symbols of the new status of foreign trade were the four coastal special economic zones (see Glossary), which were created in 1979 as enclaves where foreign investment could receive special treatment. Three of the four zones—the cities of Shenzhen, Zhuhai, and Shantou—were located in Guangdong Province, close to Hong Kong. The fourth, Xiamen, in Fujian Province, was directly across the strait from Taiwan. More significant for China's economic development was the designation in April 1984 of economic development zones in the fourteen largest coastal cities- -including Dalian, Tianjin, Shanghai, and Guangzhou—all of which were major commercial and industrial centers. These zones were to create productive exchanges between foreign firms with advanced technology and major Chinese economic networks. Domestic commerce also was stimulated by the reform policies, which explicitly endeavored to enliven the economy by shifting the primary burden of the allocation of goods and services from the government plan to the market. Private entrepreneurship and free-market activities were legalized and encouraged in the 1980s, although the central authorities continuously had to fight the efforts of local government agencies to impose excessive taxes on independent merchants. A significant economic debate during this period concerned the approach to price liberalization and whether China should adopt an approach consistent with shock therapy—sudden price liberalization—or a more gradual