Phnom Penh has traditionally been Cambodia's principal commercial center. Formerly, most wholesale and retail business was in the hands of French, Chinese, and Vietnamese. In April 1975 all private shops in the country were closed and virtually all domestic trade fell under the control of the state. Official currency was abolished in favor of barter. Following the installation of the PRK, currency was reestablished and some private trade resumed with official encouragement. Since 1983, private shops have resumed operation in Phnom Penh. Most of these shops are owned directly or subsidized by wholesalers. Goods are also sold from traveling vans or through newspaper advertisements.
In 1986, the government began collecting license fees, rents, and utility fees from private businesses and substantially increased their taxes. In the early 1990s the Heng Samrin government fell behind in its payments to government troops and bureaucrats, printing more money to meet these obligations. Without revenue this vicious cycle peaked in triple-digit inflation by 1992, when the currency was rendered worthless and pulled from circulation. Market prices rose as the currency value dropped meaning poorer Cambodians could not afford their staple food, rice. The United Nations Transitional Authority in Cambodia (UNTAC) introduced imported rice and sold it at a fixed price in an effort to halt the inflationary spiral.
Despite the economic benefits of the UN presence, political disruptions and violence in 1997 and 1998 reversed economic growth. In Cambodia depressed economic output is supplemented by goods smuggled in from Thailand and Singapore. Economic reforms became in earnest in 1999, which marked the first full year of peace for the nation in about 30 years.
As of 2001, about 80% of the population was employed in agriculture; however, the service sector is beginning to grow as the nation attempts to expand tourism. The economy is still heavily reliant on international aid.